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LABORATORY    PROBLEMS 


IN 


CIVIC    BIOLOGY 


BY 


GEORGE   WILLIAM   HUNTER,  A.M. 

HEAD    OK    THE    DEPARTMENT   OF    BIOLOGY,    DE    WITT   CLINTON 

HIGH    SCHOOL,    CITY   OF  NEW    YORK 

AUTHOR    OF    "elements   OF    BIOLOGY,"    "ESSENTIALS   OF 

BIOLOGY,"    "a   civic   BIOLOGY,"    ETC. 


AMERICAN   BOOK   COMPANY 

NEW  YORK  CINCINNATI  CHICAGO 


Copyright,  1916,  by 

GEORGE   WILLIAM   HUNTER. 

All  rights  reserved. 


HUNTER   LABORATORY'  PROBLEMS. 
W.   P.   I 


DeMcate^ 

TO    MY 

PUPILS 

WHOSE     INTEREST    AND    ENTHUSIASM    HAVE 

GIVEN  RICH    SUGGESTION    FOR   THE 

CONTENTS    OF   THIS   BOOK 


19651 


CONTENTS 

Foreword  to  Tkachkks 
I.     Directions  to  the  STri>ENT  for  Keetino  Notes  in   15i<>i.o(.^ 

=„->x>TT.»,  II'     The  Environment  of  Plants  and  Ammai.s 

1.  To  determine  the  factors  of  envirouiuent      .... 

2.  Comparison  of  a  natural  with  an  artificial  environment 

3.  To  test  my  home  environment        ...... 

4.  To  learn  the  conditions  of  my  city  environment    . 

5.  To  determine  and  to  illustrate  by  a  graph  the  changes  of  temperature 

(one  of  the  factors  of  the  environment)  during  a  given  day 

6.  To  make  a  graph  to  show  how  much  fluid  I  take  into  my  body  in  a  (hiy 

7.  May  environment  influence  public  health  ?    . 

III.     The  Interrelations  of  Plants  and  Animals 

8.  A  field  trip 

9.  How  to  know  an  insect 

10.  To  learn  to  recognize  insects  that  frequent  flowering  plant.s 

11.  To  study  the  life  history  (metamorphosis)  of  an  insect 

12.  To  learn  the  structure  and  work  of  the  parts  of  a  flower 

13.  The  cross-pollination  of  flowers      ..... 

14.  To  study  cross-pollination  in  butter  and  eggs 

15.  Special  directions  for  the  study  of  some  fall  fli>wer.s  (Kxtra) 

16.  To  find  other  pollinating  agents  besides  insects     . 

IV.     The  Functions  and  Composition  oj    Livinc  Thing 

17.  The  uses  of  the  parts  of  a  plant 

18.  To  study  the  needs  and  uses  of  the  parts  of  a  living  animal 
(Study  of  compound  micro.scope) 

19.  To  determine  the  unit  of  structure  in  plants  and  aniiiials 

20.  To  determine  some  of  the  properties  of  protoplasm 

21.  To  study  structure  and  growth  of  pollen 

22.  To  study  the  reason  for  the  growth  of  polk'ii  grains  in  flowers 

23.  To  discover  how  fruits  are  formed  .... 

24.  How  and  why  fruits  and  seeds  are  scattered 


r  \i.r. 

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30 
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CONTENTS 


PROBLEM 


V.     Plant  Growth  and  Nutrition.     Causes  of  Growth 


25.  To  find  the  relation  of  tlie  embryo  to  tlie  food  supply 

26.  To  test  for  starch 

27.  To  test  for  grape  sugar 

28.  To  test  for  fats  and  oils 

29.  To  test  for  proteins  or  nitrogenous  foods 

30.  To  test  for  the  presence  of  mineral  matter  (Optional) 

31.  To  test  for  the  presence  of  water  .... 

32.  To  test  various  food  substances  for  the  organic  nutrients  (Home  work) 

33.  To  show  how  much  water  is  needed  to  make  a  seed  germinate  (Home 

experiment)     ........... 

34.  To  determine  the  temperature  best  fitted  to  cause  peas  to  germinate 

(Home  experiment)         ........ 

35.  To  show  that  seeds  need  some  part  of  the  air  in  order  to  grow 

36.  To  show  that  food  is  needed  by  the  embryo  in  order  to  grow 

37.  Is  any  part  of  the  air  necessary  for  combustion  ?     (Demonstration) 

38.  To  test  for  oxygen  (Demonstration) 

39.  To  test  for  carbon 

40.  To  test  for  carbon  dioxide 

41 .  To  prove  that  organic  substances  are  oxidized  within  the  human  body 

42.  To  prove  that  growing  seeds  oxidize  food      .... 

43.  To  study  the  fruit  of  the  corn  plant 

44.  To  study  the  structure  of  a  grain  of  corn       .         .         .         . 

45.  To  find  the  use  of  the  endosperm  of  the  corn  grain 

46.  To  find  whether  starch  or  grape  sugar  will  dissolve  in  water 

47.  To  find  how  the  young  plant  makes  use  of  the  food  supply.     Digestion 

48.  What  changes  take  place  in  starchy  foods  in  the  mouth  ?     (Demon 

stration)  ..." 

49.  Conditions  necessary  for  the  action  of  diastase      .         .         .        '. 

50.  What  is  the  reason  for  digestion  of  starch  in  the  corn  grain  ? 


PAGE 

55 

56 
57 

57 
58 
58 
59 
60 
00 

01 

62 
62 
63 
63 
64 
65 
65 
6Q 
66 
67 
67 
67 
68 
68 

69 
69 
69 


VI.     The  Organs  of  Nutrition  in  Plants  —  The  Soil  and  its 

Relation  to  the  Roots  .... 

To  find  out  the  structure  of  roots  ....... 

To  determine  the  influence  of  gravity  on  the  direction  of  growth  of 
roots        ........... 

To  find  the  effect  of  water  on  the  growth  of  roots 
To  study  the  structure  and  purpose  of  root  hairs 

55.  To  discover  how  fluids  travel  through  roots  and  stems 

56.  To  find  out  how  root  hairs  absorb  soil  water  .... 

57.  To  determine  what  kind  of  substances  will  pass  through  a  membrane 

58.  To  test  organic  material  in  soil       ....... 

59.  To  find  what  kind  of  soil  holds  water  best 


51 
52 

53 
54 


72 
72 

73 
73 

74 
74 

75 
76 

77 
77 


|'a<;k 
78 
7H 
79 
80 
80 

84 

85 
85 


CONTENTS 

PROBLEM 

60.  What  do  plants  take  out  of  the  soil  ? 

61.  How  are  root  hairs  able  to  take  mineral  matter  out  of  the  soil  ? 

62.  What  are  root  tubercles  and  what  is  their  use  ?    . 

63.  What  is  crop  rotation  and  what  is  its  use  ?    . 

64.  What  roots  are  useful  as  food  ? 

VII.     Plant  Growth  and  Nutrition  —  Plants  Make  Food 

65.  To  prove  that  water  is  given  off  by  a  green  plant 

66.  Through  which  surface  of  a  leaf  does  transpiration  take  place  ?    . 

67.  To  determine  how  the  structure  of  a  leaf  fits  it  for  the  work  it  hius  to  do      86 

68.  To  study  the  microscopic  structure  of  a  leaf  .....      80 

69.  To  show  the  effect  of  light  on  green  leaves .80 

70.  To  determine  the  relation  of  light  to  the  presence  of  starch  in  a  green 

leaf 87 

71.  Is  a  part  of  the  air  a  factor  in  starch  making  in  leaves  '.'        .         .         .  87 

72.  The  need  of  chlorophyll  for  starch  making 88 

73.  To  consider  the  leaf  as  a  manufactory 88 

74.  To  show  that  a  gas  is  given  off  as  a  waste  product  when  green  phmLs 

make  starch 88 

VIII.     Plant  Growth  and  Nutrition  —  The  CiRrri.  \ti<>n    wi. 

Final  Uses  of  F'ood  by  Plants    ....       HI 

75.  Groups  of  plants  told  by  the  structure  of  their  stems    . 

76.  To  study  the  structure  of  a  woody  stem 

77.  To  prove  that  liquids  rise  through  steins  (Review) 

78.  To  find  out  through  which  part  of  a  woody  stem  food  passes  down 

79.  How  plants  with  special  digestive  organs  get  their  nitrogenous  food 


91 

93 
•>4 
'M 


IX.     Our  Forests,  their  Uses  and  the  Necessity  kok  thkir 

Protection     ......  9<J 

80.  To  determine  how  lumber  is  cut  and  how  to  reco-nj/x  tho  rut  in  trim  1>0 

81.  To  determine  some  uses  of  stems 97 

82.  To  determine  the  value  of  certain  woods 97 

83.  Museum  trip  for  study  of  woods 98 

84.  To  identify  common  trees  by  the  use  of  a  key 99 

X.     The  Economic  Relation  of  Green  Plants  to  M*n        .  KX) 

85.  To  determine  the  economic  importance  of  sonu'  green  plants         .         .  1(M» 

86.  To  learn  to  know  some  green  plants  harmful  to  man     ....  1«>7 

XI.     Plants  avithoft  Cmlorophvii.  in  their  1?i:i.atio\  to  Mvn  110 

87.  To  determine  the  relation  of  fungi  to  the  destruction  of  certain  trees  111 

88.  To  determine  the  conditions  favorable  for  the  growth  of  mold      .         .112 

89.  To  study  the  structure  of  bread  mold 112 


8  CONTENTS 

PEOBLEM  PAGE 

90.  What  is  fermentation  and  what  causes  it  ? 113 

91.  To  learn  to  recognize  yeast  phmts  under  the  compound  microscope    .  114 

92.  Do  yeasts  grow  wild  ? 11,5 

93.  To  determine  the  conditions  favorable  to  the  growth  of  yeast      .         .  115 

94.  AVhat  are  the  conditions  favorable  for  the  growth  of  yeast  in  bread  ? 

(Homework) .         .         .  116 

95.  How  we  proceed  to  the  study  of  bacteria 116 

96.  How  to  prepare  culture  media ,.117 

97.  To  demonstrate  a  pure  culture 118 

98.  To  determine  where  bacteria  may  be  found 118 

99.  To  study  how  rapidly  bacteria  grow     .         .         .         .         .         .         .119 

100.  What  foods  are  preferred  by  bacteria  ?.....,  120 

101.  What  effect  has  heat  upon  the  growth  of  bacteria  ?      .         .         .         .  120 

102.  To  note  the  effect  of  moisture  and  dryness  upon  the  growth  of  bacteria 

(Home  problem)    ..........  121 

103.  To  determine  the  effect  of  pasteurization  upon  the  keeping  quality  of 

milk 121 

104.  How  to  care  for  milk  bottles  at  home  .......  122 

105.  To  determine  the  bacterial  content  of  milk           .....  122 

106.  To  determine  some  of  the  most  effective  preservatives          .         .         .  123 

107.  To  determine  the  most  effective  disinfectants       .....  124 

XII.     The  Relations  of  Plants  to  Animals          .         .  127 

108.  To  study  some  biological  relations  of  plants  and  animals  in  a  balanced 

aquarium        .         ..........  127 

109.  To  learn  what  we  mean  by  the  carbon  and  the  oxygen  cycles     .         .  128 

110.  To  find  out  the  course  of  nitrogen  in  its  relation  to  plants  and  animals  129 

111.  To  prove  a  hay  infusion  is  an  unbalanced  aquarium  ....  129 

XIII.     Single-celled  Animals  Considered  as  Organisms 

112.  To  study  a  one-celled  animal  in  order  to  understand  better  (a)  its 


reactions  to  stimuli ;   (6)  the  cell  as  a  unit  of  structure 
113.    Comparative  study  of  various  forms  of  single-celled  animals  to  explain 
division  of  labor  (Extra  problem)  ..... 


115.  To  compare  reproduction  in  plants  with  that  in  animals 

116.  To  study  the  division  of  labor  in  tissues  and  organs     . 

117.  To  find  some  of  the  functions  common  to  all  animals  . 

118.  How  to  know  some  types  of  animals  in  the  animal  kingdom 


132 
1.32 


1.35 

XIV.    Division  OF  Labor.    The  Various  Forms  of  Plants  and  Animals     137 
114.    How  the  plant  kingdom  is  classified     ...... 


137 
139 
140 
141 
141 

146 


XV.     The  Economic  Importance  of  Anijials 

119.    What  Rnimal  foods  are  cheapest  in  any  locality  and  why  ?     (Home 

work) 147 


CONTENTS 


9 


PROBLEM 

120.  How  animals  may  benefit  mankind 

121.  To  find  out  bow  birds  are  of  economic  importance 

122.  What  are  the  causes  of  decrease  in  the  number  of  birds  '.' 

123.  To  study  tlie  life  liistory  of  the  mosquito      ..... 

124.  To  find  the  breeding  places  of  mosquitoes  in  any  locality  :uid  liow  t« 

destroy  them  ......... 

125.  To  determine  some  methods  of  destroying  mosfjuitoes 

126.  To  find  the  relation  of  mosquitoes  to  diseases  of  man 

127.  To  study  the  life  history  of  the  parasite  causing  malaria      . 

128.  To  study  the  life  history  of  the  typhoid  fiy  .... 

129.  To  determine  the  harm  done  by  the  fly  and  the  way  it  does  this  liarm 

130.  What  is  the  best  way  to  catch  and  destroy  flies  ?     ( Home  work) 

131.  To  determine  harm  done  by  insects 

132.  To  know  some  forms  of  animal  life  that  cause  disease 


XVI. 


133. 
134. 
135. 
13G. 
137. 
138. 
139. 
140. 
141. 
142. 
143. 
144. 
145. 

146. 
147. 

148. 
149. 


Sttdy  of 


The  Fish  and  Frog,  ax  iNTRonucroKY 
Vertebrates   . 

To  determine  how  a  live  fish  is  fitted  for  life 

To  study  food  getting  by  the  fish 

To  study  the  sense  organs  of  the  fish    . 

1  o  study  some  of  the  internal  organs  of  a  fish 

lo  study  the  skeleton  and  central  nervous  system  of  the  fish  (Kxtra 

Ilovv  fishes  are  artificially  jDropagated  ...... 

Trip  to  the  aquarium  (Optional,  in  place  of  Problems  133  and  lo8j 
To  determine  some  adaptations  in  a  living  frog  . 
Adaptations  of  appendages  for  locomotion  . 
Adaptations  for  sensation     ..... 

Adaptations  for  food  getting         .... 

Adaptations  for  breathing    ..... 

Museum  trip  to  study  the  frog  group  (Extra  problem  based  on  trij 
to  American  Museum  of  Natural  History)     .... 

To  collect  and  study  frogs'  eggs 

To  study  conditions  favorable  for  development  of  frogs'  eggs 
To  study  the  metamorphosis  of  the  frog       .... 
To  work  out  a  comparison  of  development  of  the  vertebrates 


XVII.     Heredity,  Variation,   Tl.vnt  am>  .\mm\i.   HurKPixi; 

150.  To  determine  if  there  is  individual  variation   in   any  one  niea.'^ure 

ment  of  the  members  of  a  given  class    . 

151.  To  show  variation  in  a  given  class 

152.  Does  heredity  play  any  part  in  our  lives  :'    . 

153.  To  study  the  fine  structure  of  an  egg  cell     . 

154.  How  selection  is  made  .         .         .         •         • 

155.  A  practical  result  of  selection       .... 


PAOK 

148 
148 
149 

119 

l.'.l 
l.'.l 
152 
152 
153 
154 
155 
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15<I 


150 
159 

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164 
165 
165 
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165 

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108 
169 

173 

174 
176 

177 
!> 
178 
179 


10 


CONTENTS 


170. 
171. 
172. 
173. 
174. 
175. 

176. 

177. 

178. 

179. 

180. 
181. 
182. 
183. 


PROBLEM 

156.  To  determine  some  means  of  selection  of  fruit  trees  from  the  economic 

standpoint      ......... 

157.  How  hybridization  is  accomplished  in  flowering  plants 

158.  Other  methods  used  in  plant  breeding  .... 

159.  To  determine  the  working  of  Mendel's  Law 

160.  To  determine  some  means  of  bettering,  physically  and  mentally,  the 

human  race    ......... 

161.  Are  good   mental   parts  or  qualities   capable  of  transmission  from 

parent  to  child  ?     . 

162.  Does  control  of  our  environment  have  anything  to  do  with  the  prob 

lem  of  race  betterment  ?...... 

XVIII.     The  Human  Machine  and  its  Needs 

163.  To  show  that  the  human  body  is  made  up  of  cells 

164.  To  find  out  some  functions  of  the  skin         .... 

165.  To  study  the  use  of  the  muscles  ...... 

166.  To  study  the  structure  and  uses  of  the  skeleton  . 

167.  To  find  the  relation  of  muscles  to  bones  in  the  human  body 

168.  To  study  the  joints  of  the  human  body         .... 

169.  To  get  a  preliminary  survey  of  the  internal  structure  of  the  human 

body 


PAGE 


XIX.     Foods  and  Dietaries 

How  to  determine  the  nutritive  value  of  food 

The  use  of  the  bomb  calorimeter  (Optional) 

To  find  the  value  of  food  as  a  tissue  builder  compared  with  its  cost 

To  find  the  value  of  food  as  a  source  of  energy  compared  %vith  its  price 

To  find  my  daily  Calorie  requirement  .... 

To  find  the  proportion  of  protein,  fat,  and  carbohydrate  needed  in 

my  daily  Calorie  requirement        ..... 
To  obtain  my  daily  dietary  with  the  100  Calorie  table  of  Fisher  and 

to  make  the  necessary  corrections  in  my  dietary  . 
To  compare  your  day's  total  Calories  with  the  estimated  needs  of  a 

person  of  your  age  doing  the  kind  of  work  which  you  do 
To  find  the  relation  of  the  value  of  food  to  its  cost  in  the  family 

dietary   ........... 

To  study  some  forms  of  food  adulteration  and  some  means  of  detect 

ing  adulterants 

To  determine  the  effect  of  alcohol  upon  raw  white  of  egg    . 

To  deternnne  the  amount  of  alcohol  in  some  patent  medicines    . 

To  test  for  acetanilid  and  to  know  some  patent  medicines  containing  it 

What  are  tlie  harmful  materials  formed  in  catarrh  cures  and  soothing 

sirups? ,         .        .        ,         . 


215 


CONTEXTS 


11 


PROBLEM 

XX.     Digestion  and  Ahsoimtmin  . 

184.  To  compare  the  digestive  system  of  a  frog  with  that  <»f  iiiai 

185.  To  study  my  own  teeth 

186.  To  demonstrate  the  function  and  structure  of  a  simple  j;land 

187.  To  find  the  use  of  digestion 

188.  To  determine  the  conditions  most  favorable  fur  ga.siric  digestion 

189.  To  determine  another  effect  of  gastric  juice 
100.  To  note  the  action  of  pancreatic  juice  on  starch  . 
lUl.  To  note  the  effect  of  pancreatic  juice  on  oils  and  fats 

192.  To  study  the  effect  of  artificial  pancreatic  juice  on  i^rotein 

193.  To  find  one  action  of  bile 

194.  To  study  the  method  and  place  of  absorption  in  the  human  body 

195.  To  understand  the  structure  of  a  villus 

196.  How  may  foods  be  absorbed  by  the  villi  ?    . 

197.  To  find  the  pathway  of  absorbed  foods 

XXI.     The  Blood  and  its  Circulation 

198.  To  prove  that  blood  contains  nutrients 

199.  To  study  the  corpuscles  of  the  blood    .... 

200.  To  determine  the  effect  of  oxygen  and  carbon  dioxido  upon  tlu- 

201.  To  study  the  structure  of  the  heart      .... 

202.  To  study  the  circulation  of  the  blood  .... 

203.  To  determine  the  rate  of  your  own  heartbeat 

204.  What  is  the  effect  of  hard  mental  work  on  the  pulse  beat '.' 

205.  What  effect  has  exercise  on  the  heartbeat  ? 

206.  How  to  stop  the  flow  of  blood  in  case  of  an  accident  . 

XXII.     Respiration  and  Excretion 

207.  To  compare  the  structures  of  the  lungs  of  the  frog  and  of  man 

208.  To  determine  changes  that  take  place  in  air  in  the  lungs 

209.  To  find  the  capacity  of  the  lungs  .... 

210.  To  study  the  mechanics  of  respiration 

211.  To  study  the  part  the  ribs  play  in  respiration 

212.  What  is  the  function  of  the  diaphragm  ?      .         .         . 

213.  To  find  out  what  becomes  of  the  oxygen  in  the  lungs 

214.  To  make  a  study  of  ventilation 

215.  To  study  air  for  presence  of  du.st  (Home  experiment) 
210.  To  determine  the  best  method  of  cleaning  a  room 

217.  What  makes  a  crowded,  closed  room  uncomfortable  ? 

218.  To  study  the  structure  of  the  kidney    .... 

219.  The  skin  as  an  organ  of  excretion  and  heat  control 

XXIII.     Body  Control  and  IIauit  Formation 

220.  How  are  we  aware  of  the  world  about  us  ? 


220 

221 
222 
223 
•JJ  \ 
224 
225 
225 
225 
22r, 

226 


blood 


228 

232 

232 

2:W 
2:^4 

235 
2:}6 
237 
237 
237 
238 

240 

211 
241 
242 
242 
213 
243 
244 
244 
245 
245 
246 
24«» 


251 
251 


12 


CONTENTS 


PROBLEM 

221 


•  • 


To  determine  what  parts  of  the  body  are  most  sensitive  to  (a)  touch, 
(6)  heat  and  cold  ...... 

222.  To  study  the  anatomy  of  the  nervous  system 

223.  To  study  the  structure  and  use  of  neurons  . 

224.  What  is  a  reflex  action  ? 

225.  To  compare  the  reaction  time  of  hearing  and  toucli 
22G.    To  compare  a  reflex  action  with  an  act  of  thought 

227.  To  study  habit  forming 

228.  To  study  the  mechanism  of  habit  formation 

229.  To  consider  some  harmful  habits 

230.  How  to  go  to  work  to  form  good  habits 

231.  To  determine  the  relation  between  taste  and  smell  with  reference  to 

food  flavors    ........... 

232.  How  to  find  out  certain  defects  of  vision  in  the  laboratory 

233.  What  are  some  of  the  effects  of  alcohol  on  the  nervous  system  ? 

XXIV.     Man's  Improvement  of  his  Environment     . 

234.  How  to  ventilate  my  bedroom  (Home  problem) 

235.  To  compare  the  duster  and  the  dry  cloth  with  the  moist  cloth  in 

cleaning  the  schoolroom         ........ 

236.  What  should  I  eat  for  luncheon  ? 

237.  To  make  a  sanitary  map  of  my  own  environment         .... 

238.  To  determine  the  bacterial  content  of  different  grades  of  milk     . 

239.  To  determine  the  bacterial  content  of  some  kinds  of  water 

240.  To  determine  some  of  the  problems  of  water  supply  and  sewage  dis- 

posal for  a  city 

241.  Is  typhoid  a  city  or  a  country  disease  ? 

242.  What  is  the  annual  cost  to   New  York  city  of  some   preventable 

diseases  ?.......••.• 

243.  What  are  the  chief  causes  of  death  in  a  city  ?...-. 

244.  To  study  the  relation  of  the  death  rate  to  the  season  .... 

245.  To  find  a  relation  between  flies  and  mortality 

246.  To  determine  the  number  of  school  children  who  needed  treatment 

for  different  diseases  in  New  York  city,  1914-1915 

247.  How  to  discover  the  presence  of  adenoids 

248.  To  find  some  ways  of  preventing  the  spread  of  disease 

249.  First  aid  in  the  home.     A  summary  of  what  to  do  and  how  to  do  it  . 


PAGE 

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253 
254 

254 
254 
255 
255 

256 
257 
257 

258 
259 
259 

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263 

263 
.264 
265 
266 
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272 
272 

273 
274 
274 

277 


FOREWORD   TO   TEACHERS 

It  has  become  the  fashion  in  modern  pedai!;o^;y  to  teach  by 
the  so-called  "  Problem  Method,"  that  is,  to  attempt  to  make  the 
child  solve  problems  from  the  very  beginning  of  his  work  in  the 
elementary  school.  But  it  is  one  thing  to  say  to  the  child,  "  Here 
is  your  problem,  solve  it,"  and  quite  another  thing  to  lead  him 
through  the  several  thought  processes  necessary  to  the  solution 
of  the  problem.  A  child  of  six  may  be  taught  to  tliink,  and 
think  clearly,  if  he  is  guided  so  that  he  makes  a  generalization 
after  comparison  with  what  his  senses  tell  him  he  knows.  The 
mistaken  notion  of  our  educational  system  has  been  that  (hill 
and  drill  alone,  pure  memory  work,  is  only  fitted  for  the  mental 
life  of  our  young  children.  Nothing  is  further  from  the  actual 
truth.  The  mental  growth  of  the  child  is  an  evolutionar}-  growth, 
but  it  is  a  development  based  more  upon  his  reaction  to  the 
world  than  upon  the  mechanism  within  his  body.  The  nei-vous 
system  and  its  connectives  develop  early.  Our  education  of  the 
nervous  system,  based  on  the  theory  that  the  nervous  systeui  is 
not  well  developed,  makes  simply  for  the  formation  of  concepts. 

Concept  forming  and  concept  enlargement  are  a  necessary  jiart 
in  any  scheme  of  education,  but  the  method  and  the  form  of  straigiit 
thinking  are  of  even  greater  importance.  Problems  in  life  are  not 
solved  by  knowing  dates  or  facts,  no  matter  how  inu)()rtant  or 
interesting  these  may  be.  The  methods  of  icaching  a  conclusion, 
of  weighing  evidence,  of  making  decisions  upon  the  merits  of  the 
facts  in  a  case,  of  thinking  straight  from  evidence  gained  from 
given  data, —  these  are  the  habits  of  mind  which  iwv  wortli  far 
more  to  a  child  than  the  actual  im])act  with  the  subject  matter 
in  a  textbook.     Hence  pure   science,    the   handmaiden   of   clear 


N.  C  State  ( 


14  FOREWOKD   TO   TEACHERS 

thought,  needs  emphasis  placed  on  method  above  all  else.  And 
the  method  of  science  is  best  found  in  the  laboratory. 

Dr.  H.  E.  Walter  has  well  summed  up  the  real  use  of  laboratory 
work  in  the  following  words : 

"  The  laboratory  method  was  such  an  emancipation  from  the 
old-time  bookish  slavery  of  pre-laboratory  days  that  we  may  have 
been  inclined  to  overdo  it  and  to  subject  ourselves  to  a  new  slavery. 
It  should  never  be  forgotten  that  the  laboratory  is  simply  a  means 
to  the  end ;  that  the  dominant  thing  should  be  a  consistent  chain 
of  ideas  which  the  laboratory  may  serve  to  elucidate.  When, 
however,  the  laboratory  assumes  the  first  place  and  other  phases 
of  the  course  are  made  explanatory  to  it,  we  have  taken,  in  my 
mind,  an  attitude  fundamentally  wrong.  The  question  is,  not 
what  types  may  be  taken  up  in  the  laboratory,  to  be  fitted  into  the 
general  scheme  afterwards,  but  what  ideas  are  most  worth  while 
to  be  worked  out  and  developed  in  the  laboratory,  if  that  hap- 
pens to  be  the  best  way  of  doing  it,  or  if  not,  some  other  way  to 
be  adopted  with  perfect  freedom.  Too  often  our  course  of  study 
of  an  animal  or  plant  takes  the  easiest  rather  than  the  most 
illuminating  path.  What  is  easier,  for  instance,  particularly  with 
large  classes  of  restless  pupils  who  apparently  need  to  be  kept  in 
a  condition  of  uniform  occupation,  than  to  kill  a  supply  of  animals, 
preferably  as  near  alike  as  possible,  and  set  the  pupils  to  work 
drawing  the  dead  remains  ?  This  method  is  usually  supplemented 
by  a  series  of  questions  concerning  the  remains  which  are  sure  to 
keep  the  pupils  bus}'-  a  while  longer,  perhaps  until  the  bell  strikes, 
and  which  usually  are  so  planned  as  to  anticipate  any  ideas  that 
might  naturally  crop  up  in  the  pupiFs  mind  during  the  drawing 
exercise. 

"  Such  an  abuse  of  the  laboratory  idea  is  all  wrong  and  should 
be  avoided.  (The  ideal  laboratory  ought  to  be  a  retreat  for  rainy 
days;  a  substitute  for  out  of  doors;  a  clearing  house  of  ideas 
brought  in  from  the  outside.  Any  course  in  biology  which  can 
be  confined  within  four  walls,  even  if  these  walls  be  of  a  modern, 
well-equipped  laboratory,  is  in  some  measure  a  failure.  Living 
things,  to  be  appreciated  and  correctly  interpreted,  must  be  seen 
and  studied  in  the  open  where  they  will  be  encountered  through- 


FOREWORD   TO   TEACHERS  15 

out  life.  The  place  where  an  animal  or  plant  is  found  is  just  as 
important  a  characteristic  as  its  shape  or  function..  Iiiipossihlo 
field  excursions  with  large  classes  within  school  hours,  wliich  only 
bring  confusion  to  inflexible  school  programs,  are  not  necessary  to 
accomplish  this  result.  Properly  achninistered,  it  is  without 
doubt  one  of  our  most  efficient  devices  for  developing  l)i()logicaI 
ideas,  but  the  laboratory  should  be  kept  in  its  proper  relati(jn  to 
the  other  means  at  our  disposal  and  never  be  allowed  to  degenerate 
either  into  a  place  for  vacuous  drawing  exercises  or  a  biological 
morgue  where  dead  remains  are  viewed." 

Teaching  to  think  is  not  a  sinecure  for  the  teacher.  But  by 
proper  use  of  the  laboratory  material  and  the  laboratory  period, 
we  may  make  a  brave  start  toward  this  goal.  One  preconceived 
notion  of  a  laboratory  period  is  a  time  in  which  the  pupil  works 
alone  from  his  specimen  in  order  to  interpret  something  which  you 
and  I  know  is  there  but  of  which  he  is  ignorant.  The  metliod  of 
Agassiz  may  be  fitted  for  the  graduate  university-  student,  but 
it  must  be  modified  for  the  immature  pupil  of  the  high  school. 
We  must  throw  away  our  college  and  high  school  laboratory 
(5onception  and  place  ourselves  in  the  laboratory  as  a  pupil.  Be 
a  leader  in  a  discussion  which  will  center  around  the  specimens 
in  the  pupil's  hands;  present,  in  connection  witli  the  laboratory 
material,  some  definite  problems  relating  if  possible  to  some  phase 
of  activity  of  the  material  in  hand,  something  vital  in  the  mind  of 
the  pupil.  Lead  the  discussion  (using  the  printed  ([uestioiis  that 
follow,  but  augment  them  with  others  that  will  naturally  arise 
during  the  discussion)  toward  the  solution  of  some  definite  phase 
of  the  problem  in  hand.  ('Allow  conversation  among  the  pupils; 
get  as  many  ideas  from  different  pupils  as  you  can;  i)it  the 
brighter  ones  against  each  other  and  the  spirit  of  competition  will 
incite  the  dull  ones  to  add  their  mites.  But  guide  the  discussion 
toward  a  goal,  —  that  is  your  function  as  a  teacher.  ,  Do  not  be 
afraid  to  tell  when  it  is  time  to  give  information  and  do  not  be 
afraid  to  say,  "  I  don't  know." 

Ultimately  the  time  will  come,  when  the  discussion  of  facts  as 
pupils  see  them  has  reached  the  place  when*  a  conclusion  may 
safely  be  reached.     Now  is  the  place  for  the  teacher,  again  for- 


16  FOREWORD   TO   TEACHERS 

nuilalin^-  the  i)i()l)l(Mn,  to  give  the  class  —  this  time  as  individuals 

—  opportunity  to  write  their  generalizations,  or  their  answer  to 
the  problem,  in  th(^  form  of  a  good  English  sentence  or  paragraph. 

After  this  is  done  reading  of  conclusions  by  several  individuals 
allows  by  comparison  the  fixing  of  the  correct  conclusion  in  the 
minds  of  all.  Time  is  thus  obtained  for  rectifying  the  tangled 
ideas  of  those  members  of  the  class  less  able  to  cope  with  the 
prol)lcm.  Incidentally,  this  does  away  to  a  large  extent  with 
correcting  laboratory  papers,  as  the  student,  by  comparison  with 
the  final  corrected  conclusion,  does  his  own  correcting.  This 
makes  for  more  effective  science  teaching,  as  the  teacher  of  science 
should  be  a  leader,  not  a  drudge. 

Sometimes  a  generalization  is  asked  for,  perhaps  before  the 
pupil  is  ready  for  it,  for  the  object  is  to  incite  the  worker  to  be 
something  more  than  a  blind  reader  of  directions  and  a  maker  of 
drawings.     An  immature  conclusion  —  even  a  wrong  conclusion 

—  in  the  form  of  a  generalization,  is  better  for  the  pupil  than 
contentment  with  no  conclusion  at  all.  If  the  child  can  be  stim- 
ulated to  think  from  the  very  beginning,  then  do  not  worry  at 
first  over  the  exactitude  of  his  conclusion  so  long  as  he  is 
trained  in  the  making  of  judgments.  It  is  the  thought  process 
we  are  after  at  first,  the  method  of  thinking  more  than  the  scien- 
tifically exact  result.  The  latter  will  come  gradually  as  the  hori- 
zon of  the  pupil  widens.  We  all  know  our  concepts  change. 
What  is  an  exact  concept  at  fourteen  would  not  stand  the  test  at 
twenty-four  or  at  forty-four.  It  is  a  true  maxim  that  experi- 
ence is  the  best  teacher.  Be  that  so,  even  experience  does  not 
make  thinkers  of  us,  unless  we  know  how  to  profit  by  her  teachings. 

Tlie  pages  that  follow  are  intended  to  act  as  a  guide  and  a  stim- 
ulus to  the  pupil  so  that  he  will  be  led  to  see  beyond  the  printed 
words  in  the  textbook.  Many  children  do  not  know  how  to  use 
their  text.  Diagrams  and  figures  mean  nothing  to  them.  The 
old-fashioned  thought  questions  found  in  so  many  textbooks  of 
twenty-five  years  ago  were  of  great  value  because  they  crystal- 
lized the  problem  before  the  student  and  focused  the  attention 
on  the  essentials  within  a  given  paragraph.  The  pedagogic  value 
of  questions  on  diagrams  is  great.     The  use  of  graphs  is  a  part 


FOREWORD   TO   TEACHERS  17 

of  every  educated  person's  equipment  in  life.  These  fiicluis  are 
strongly  emphasized  in  the  working  out  of  the  problems  of  this 
book. 

An  attempt  has  been  made  by  the  author  to  be  practical  as  well 
as  logical,  and  to  gain  interest  through  the  practical  treatment  of 
things  that  are  familiar  to  the  pupil.  Whenever  possible,  techni- 
cal terms  are  done  away  with,  and  experiments  are  made  as  simple 
as  possible  without  destroying  their  scientific  value. 

In  general,  a  few  large  group  problems  have  been  made  that 
directly  explain  the  text  of  the  author's  Civic  Biology,  which  this 
manuscl  is  intended  to  interpret  in  the  laboratory.  In  addition  io 
these,  other  secondary  but  closely  associated  problems  are  added 
with  less  explicit  directions,  so  as  to  give  opportunity  for  some 
mental  activity  in  their  solution  on  the  part  of  the  pupil.  It  is 
not  expected  that  all  the  problems  are  to  be  attempted  in  a  year's 
course  in  elementary  biology,  but  a  choice  should  be  made  bj-  the 
instructor  of  what  he  considers  the  most  important  for  his  own 
particular  classes. 

The  author  wishes  especially  to  thank  Messrs.  George  T.  Hastings, 
John  W.  Teitz,  and  Frank  M.  Wheat  of  the  Department  of  Biology 
in  the  De  Witt  Clinton  High  School  for  their  many  helpful  sug- 
gestions and  for  certain  of  the  exercises  and  excellent  drawings 
accompanying  many  of  the  experiments.  All  members  of  the 
department  have  in  one  way  or  another  given  ideas  to  tlie  lab- 
oratory exercises  which  follow,  and  my  sincere  personal  thanks 
are  due  to  them  as  well. 

The  author  also  wishes  to  make  acknowledgment  to  the  various 
sources  from  which  the  experiments  and  lal)oratory  exercises  of 
the  following  pages  were  adapted.  Of  especial  value  in  this 
respect  have  been  the  numerous  publications  of  the  Department 
of  Agriculture,  the  Bureau  of  Fisheries,  and  the  various  health 
reports  of  state  and  city  Boards  of  Health.  The  Cornell  Uni- 
versity Reading  Course  Pamphlets  and  tlieir  Xature  Study 
Leaflets  have  also  been  of  much  service,  especially  in  the  work  on 
dietetics.  In  the  laboratory  study  of  dietaries  the  100  Calorie 
Portion  Table  of  Irving  Fisher,  comi)iled  from  the  Journal  of  the 
American  Medical  Association,  Vol.    XL\TII,  No.    16,  has  also 

HUNTER   LAB.    PROS. — 2 


18  FOREWORD   TO  TEACHERS 

been  useful.  For  the  idea  of  the  biological  survey  of  a  neighbor- 
hood, I  wish  to  thank  Professor  Clifton  F.  Hodge,  and  his  sugges- 
tive and  inspiring  Nature  Study  and  Life.  William  H.  Allen  has 
kindly  permitted  the  use  of  some  of  his  excellent  tables  compiled 
in  Civics  and  Health;  to  him  I  also  extend  hearty  thanks. 

The  arrangement  of  the  laboratory  problems,  previously  used 
by  Mr.  Sharpe  and  myself  in  the  manual  accompanying  the 
Essentials  of  Biology,  claims  no  originality  except  in  application. 
The  laboratory  problem  form  was  first  worked  out,  so  far  as  I 
am  aware,  by  Arthur  Stone  Dewing  in  a  manual  prepared  for  the 
Knott  Apparatus  Company.  This  book  adapts  the  problem 
method  to  young  students  in  an  urban  community. 

The  problem  questions  given  at  the  end  of  each  chapter  follow 
the  old  and  tried  plan  of  summary  questions  given  at  the  end  of  a 
chapter  in  a  textbook  for  the  purpose  of  bringing  together  the 
important  points  in  the  mind  of  the  pupil.  These  questions  are 
so  formulated  as  to  make  the  student  use  the  material  worked  over 
in  the  laboratory,  together  with  the  additional  information  gleaned 
from  the  text,  so  as  to  reach  definite  and  clear-cut  conclusions 
concerning  the  essential  points  in  the  chapter  just  finished. 

Nearly  every  laboratory  chapter  has  been  prefaced  with  a  few 
words  to  the  teacher.  These  are  important,  as  they  serve  to  indi- 
cate the  viewpoint  of  the  writer  and  the  philosophy  underlying 
the  various  parts  of  the  book.  It  is  hoped  that  these  suggestions 
may  add  clarity  and  help  those  who  use  this  book  to  organize 
their  work. 


LABORATORY  PROBLEMS  L\  ("1\  IC 

BIOLOGY 

I.   DIRECTIONS    TO    THE    STUDENT     FOR     KEEPING 

NOTES   IN   BIOLOGY 

It  is  suggested  that  two  notebooks  be  used.  In  one,  the  home 
notebook,  all  written  notes,  either  dictation  notes  or  those  looked 
up  frorn  original  sources,  should  be  placed.  The  other,  a  lal)ora- 
tory  notebook,  should  be  used  for  drawings  and  written  work 
done  in  class  as  well  as  experiments  and  demonstrations  performed 
in  the  laboratory.  The  illustrations  on  pages  20  and  21  will  serve 
to  indicate  the  appearance  of  a  blank  page  after  laboratory  w jrk 
has  been  done. 

All  written  work  should  be  in  ink,  and  great  care  should  be 
exercised  not  only  in  the  construction  of  good  English  sentences, 
but  also  in  writing.  A  careless,  slovenly  page  may  spoil  otherwise 
excellent  work. 

Especial  care  should  be  exercised  in  making  your  drawings. 
A  hard  pencil  (HHHHH)  sharpened  to  a  needlelike  point  shouhl 
be  used.  Do  not  shade  your  drawings.  Make  each  line  mean 
something  definite.  We  do  not  want  artistic  sketches  so  much  as 
we  want  accurate  representations  of  what  ytni  see.  Uememl)er  a 
good  workman  uses  good  tools;  therefore  use  a  sharp,  pencil,  a 
clean  eraser,  and  an  active  hand  and  brain.  Drawing  witliout 
thought  of  what  you  are  doing  is  only  busy  work  and  does  you 

no  good. 

Among  the  most  important  of  your  laboratory  exercises  are  your 
experiments.  An  experiment  should  have  four  stei)s,  each  of 
which  is  separated  from  each  of  the  others  by  a  paragraph  headmg. 

19 


20 


DIRECTIONS   TO   THE   STUDENT 


The  four  steps  are  1,  the  problem ;  2,  the  method  used  ;  3,  the  obser- 
vations made;    and  4,  the  conclusion  reached. 


layn/.  /S,l'^/6.  (U/^  d/CuUyoiny 


<Zyir?7V  ^^^"^rOytcJi/ 


o 


o 


0=  Osedi    i<\>  3a^ij  das,t- 


VJAxrifU/yT^      lU^ 


AJUiA^y, 


'(MA^{/vn^  AJil/ijy  /t^'^M-t^^ 


CAiAMxmy 


ycmy. 


(j/Jj-dlAyVx^Xumj:  <:zJyKJO  _AZjuL^  A^^^^ 
/O-mAy  ^tAju  AAyy-TnJX'LraJjAy  rOtAAy  Carved^. 

jJlAAU^  ZtA/xXj  JjnJUL  C/XAJj^JU  JiurrUUAJ-tkMji^  Stxr- 


Xyn~ 


'^  JjxX- 


.Mjl^J.^  . 


Under  the  heading  problem  you  should  tell  exactly  what  you  are 
trying  to  solve ;  your  method  should  describe  exactly  how  you  went 
to  work  to  set  up  your  experiment  and  what  you  subsequently 
did ;    the  observations  are  what  you  saw  (as  a  result  of  what  you 


DIRECTIONS   TO   Till-:   STKDIOXT 


21 


did);    and  your  conclusion  fihould  ])v  rcacluMl  only  after  wci^iliinn 
the  evidence  you  have  obtained  in  your  expcriiiicnt  and  ilicii  aj)- 


o 


o 


/[^Ke  StLcd^  of  tlic'BeaTL  sSeecL 


tei^k 


irvb 


"tKe,  CjiOdtvo  or  k»ab^' 
pIcxJv-t  ap-oL  tKe-  seeoL 

Cocxt  or  tjLstoL. 

c/  "LuJo  Co'tyTec3LoJv5  ,  ■t}^Q> 
Xj^  po  c  oi-xl.  . 


c3.eYG-Xo-Tos  iTvto  't-ir^Q.   r^oot    oTvct   stc,>^^.        -^ 
^tv^   aT\o"t}\e»~  ex  ^eT- iTi^exu't       1    provG<^    "trvcx7~ 


0"tjaT"C-  IV 


OTV>, 


cTov-G,    O.    vci-'^  'posture 


Qxl      CL  c5reoL$e.    Spot.    5Ko>v<t^  -*^W  ^rcsc*t'«c 


^ 


plying  it  as  a  definite  and  ea:ad  result  of  an  act  of  tliou^ht.  An 
experiment,  above  all  other  things,  should  teach  us  to  think 
straight;  for  straight  and  definite  thinking  is  oin*  greatest  asset  in 
later  life. 


22  DIRECTIONS    TO   THE  STUDENT 

Problem   Questions 

1.  Why  should  we  write  laboratory  work  in  ink  but  make  our 
drawings  in  pencil? 

2.  Why  should  our  records  be  written  instead  of  oral? 

3.  What  are  the  four  steps  of  an  experiment? 

4.  How  might  an  experiment  be  of  use  in  everyday  life? 

5.  Why  did  Huxley  call  science  ''  organized  common  sense  "? 


11.   THE    ENVIRONMENT    OF    PLANTS    AND    ANIMALS 

Problem.  —  To  discover  some  of  tJie  factors  of  the  rnvironincnt 
of  plants  and  animals. 

(a)  Environment  of  a  plant. 

(b )  Enviromnent  of  an  anin lal . 

(c)  Home  environment  of  a  girl  or  hoij. 

Laboratory  Suggestions 

Laboratory  demonstrations.  —  Factors  of  tho  onxTronment  of  a  Ii\i:ijj 
plant  or  animal  in  the  vivarium. 

Home  exercise.  —  The  study  of  the  factors  making  up  my  own  environ- 
ment and  how  I  can  aid  in  their  control. 

To  THE  Teacher.  —  This  chapter  may  be  made  one  of  the  most  vital  in  tho 
course  by  introducing  in  a  broad  way  what  the  environment  pives  to  the  living 
things  which  are  within  it,  how  plants  and  animals  are  limited  by  their  environment, 
and  how  man  alone  of  all  living  creatures  may  change  and  modify  his  environ- 
ment for  better  or  for  worse.  This  last  problem  is  fundamental  to  all  the  work  tlwit 
is  to  follow.  This  introductory  chapter  gives  the  child  the  keynote  of  the  problems 
which  follow  and  enlists  his  sympathy  and  interest  from  the  first,  for  it  sliows  him 
that  biology  is  a  very  human  subject  and  one  vital  to  the  understanding  of  how  to 
better  his  environment.  It  is  understood  that  the  problems  as  outlined  are  pcssiblo 
of  many  modifications,  the  environment  of  the  pupils  serving  as  the  guide  to  the 
type  of  questions  to  be  given.  The  needs  of  city  children  and  the  condition  of  their 
environment  differ  in  many  ways  from  those  of  country  children.  liut  the  fun- 
damental factors  of  the  environment  are  the  same,  and  by  comparison  should  be 
shown  to  be  the  same. 

Problem  1 :  To  determine  the  factors  of  environment. 

Method  and  Observations.  —  What  is  a  factor  in  aritliinotic? 
In  algebra?  How  might  the  term  be  usctl  in  speaking  of  our 
surroundings  ? 

Note.  —  The  environment  of  a  living  thing  is  that  which  surrounds  it  and  frr>m 
which  it  receives  certain  materials  necessary  for  its  life. 

What  is  your  environment?  Clive  e.xamph^s  of  some  diU'ereiit 
kinds  of  environments.  (See  Hunter's  Civic  Biology,  Chap.  IL) 
Explain  the  term  ''  factors  of  environment." 

23 


24       ENVIRONMENT   OF  PLANTS   AND  ANIMALS 

Home  Work.  —  Determine  the  factors  of  the  environment  of 
a  plant;  of  some  wild  animal;  of  a  cat  or  a  dog  (domesticated 
animals) ;  of  3^ourself .  Bring  to  class  a  written  statement  of 
your  answers.  ' 

Having  compared  these  different  living  things  in  their  differ- 
ent environments,  decide  what  factors  are  common  to  all  envi- 
ronments. 

Conclusion.  —  1.  What  are  the  factors  in  the  environment 
of  living  things  ? 

2.   Tabulate  the  factors  as  suggested  below : 


Plant 

^Tviirval 

I^ctru 

Factors  of 
Environment 

JPi^ohleni  2 :  Compwidson  of  a  natural  with  an  artificial  en- 
viromnent. 

Method  and  Observations.  —  Determine  what  is  added  to  or 
subtracted  from  your  home  environment  to  make  it  different  from 
the  natural  environment  of  the  country.  Make  two  columns. 
In  the  first,  place  the  factors  of  a  natural  environment.  In  the 
second,  place  the  factors  of  the  environment  in  a  city  or  town. 


TS  atixrctl 

Qi^ti^ici  al 

Remember  that  the  city  has  various  agencies  which  add  to  the 
air  certain  substances ;  that  housing  conditions  are  changed ; 
that  the  earth  is  covered  by  pavement ;  and  that  water  supplies 
and  disposal  of  waste  through  sewers  are  artificial  factors.  Think, 
too,  of  many  other  ways  in  which  the  city  environment  is  changed. 


%  C.  suite  ColUge 


PROBLEM  3 


25 


Put  down  all  the  artificial  things  that  havo  boon  nMvd  to  or  sub- 
tracted from  your  home  environment  lo  in.ikr  a  dilTurenl  from  a 
natural  environment. 

Conclusion.  —  In  what  respects  does  a  city  ciivironincnt  difTcr 
from  that  of  the  country? 

Problem  3 :  To  test  my  home  eiivironnLciit. 

Method  and  Observations.  —  Usin^-  tlu*  hnns(»  score  card  pivcn 
below,  estimate  the  condition  of  your  home  environment .  This  is 
an  exercise  for  your  own  use  and  need  not  he  shown  in  dans  unless 
you  so  desire.     When  in  doubt  consult  your  teacher. 


House  Score  Card 


Rooms 
Light  10,  gloomy  5,  dark  0       ... 
Well  ventilated  1.5,  poorly  7,  badly  0 
Repair :  good  5,  fair  3,  poor  1,  bad  0 
Clean  10,  soiled  5,  dirty  2,  filthy  0   . 


I 

11 

III 

IV 

V 

VI 

VII 

VIII 

— 

1 

i! 


""lo 
15 

5 

10" 


5 
3 


One  person  to  room  10,  2  to  room  8,  3  to  room  4,  4  or  more  0  .        10 

Sinks  j 

Construction  :   good  5,  fair  2,  bad  1 

Water-closet  I 

Construction:   good  3,  fair  2,  poor  1,  bad  0 

Condition:   clean  3,  dirty  1,  filthy  0 3 

1  compartment  for  1  family  3,  for  2  families   1,  for  more  than  i 

2  families  0 • -^ 

Cleanliness 
1  bath  tub  for  1  apartment  3,  for  more  than  1  apartnuiil    1.  ii<. 

bath  0 -^ 

Personal  cleanhness :  very  clean  7,  fairly  cU'an  .'>,  dirty  2.  lihliy  0  i 7 

Washing 

Stationary  tubs  3,  removable  2,  no  tubs  0 -^ 

Cleanhness  of  clothing  :  very  clean  7,  fairly  clean  .">,  dirty  "J.  liithy  O  '        7 

Meals 

Regular  4,  irregular  2,  uncertain  0 * 

Amount  and  kind  of  food  :   good  4,  fair  2.  poor  I.  I'a.l  n       . 
Cooking:   very  clean  4,  clean  3,  dirty  1,  fiUliy  0 
Refrigeration  :   good  4,  fair  2,  poor  1,  non(>  0 


4 

\ 

1 


1(NI 


26       ENVIRONMENT   OF   PLANTS   AND  ANIMALS 


Definitions  of  Terms  used  in  House  Score  Card^ 

Rooms  :  Light  —  Light  enough  to  read  easily  in  every  part.  (In  estimat- 
ing the  light,  ventilation,  and  repair  of  an  apartment,  di\ide  the 
sum  of  the  scores  of  all  the  rooms  by  the  number  of  rooms.) 

Gloomy  —  Not  light  enough  to  read  easily  in  every  part,  but  enough 
to  see  one's  way  about  readily  when  doors  are  closed. 

Dark  —  Too  dark  to  see  one's  way  about  easily  when  doors  are  closed. 

Well  Ventilated  —  With  window  on  street  or  fair-sized  3'ard. 

Poorly  Ventilated  —  With  ^dndow  opening  on  a  shallow  yard  or  on  a 
narrow  court,  open  to  the  sky  at  the  top,  or  else  with  5x3  inside 
window  (15  square  feet)  opening  on  a  well-ventilated  room  in  same 
apartment. 

Badly  Ventilated  —  With  no  window  on  the  street,  or  on  a  yard,  or 
on  a  court  open  to  the  sky,  and  Math  no  window,  or  a  very  small 
window,  opening  on  an  adjoining  room. 

In  Good  Repair  —  No  torn  wall  paper,  broken  plaster,  broken  woodwork 
or  flooring,  nor  badly  shrunk  or  warped  floor  boards  or  wainscoting, 
lea\ang  large  cracks. 

In  Fair  Repair  —  Slightly  torn  or  loose  wall  paper,  shghtly  broken 
plaster,  warped  floor  boards  and  wainscoting. 

In  Bad  Repair  —  Very  badly  torn  wall  paper  or  broken  plaster  over  a 
considerable  area,  or  badly  broken  woodwork  or  flooring.  (Rooms 
not  exactly  coinciding  \\dth  any  of  the  three  classes  are  to  be  included 
in  the  one  the  description  of  which  comes  nearest  to  the  condition.) 
Sinks  :  Good  —  Iron,  on  iron  supports  mth  iron  back  above  to  prevent 
splashing  of  water  on  wall  surface,  in  light  location,  used  for  one 
family.     Water  direct  from  city  water  mains  or  from  a  clean  roof  tank. 

Bad  —  Surrounded  by  wood  rims  with  or  mthout  metal  flushings,  space 
beneath  inclosed  Tvdth  wood  risers ;  dark  location,  used  by  more  than 
one  family ;    water  from  dirty  roof  tank. 

Fair  —  Midway  between  above  two  extremes. 
Water-closet:    Good — Indoor   closet.     In   well-lighted  and  ventilated 
location,  closet  fixture  entirely  open  underneath,  abundant  water  flush. 

Fair  —  Indoor  closet,  poor  condition  —  badly  lighted  and  ventilated 
location,  fixture  inclosed  with  wood  risers,  or  poor  flush. 

Poor  —  Yard  closet  —  separate  water-closet  in  indi\adual  compartment 
in  the  yard. 

Bad  —  School  sink  —  sewer-connected  privy,  having  one  continuous 
vault  beneath  the  row  of  indi\ddual  toilet  compartments. 

Conclusion.  —  1 .  Is  my  home  environment  as  good  as  it  should  be  ? 
2.    How  might  I  improve  it  ? 

1  This  and  the  following  are  modified  from  Allen,  Civics  and  Health,  Ginn  and 
Company. 


PROBLEiM   4 


27 


Problem  4:  To  Team  fJir  ronditions  of  nnj  cil ij  rnriinniiLt  iil. 
Method  and   Observations.  —  Uso  this  scoic  c.iid   in  m   manner 
similar  to  that  of  your  last  exercise.     .Iii(l^<'  cnch  item  carcfullv. 


Score  Card  tor  Citizens'  Use 


Schoolhouse:  Well  ventilated,  20;  badly,  0-10  .  . 
Cleaned  regularly,  20  ;  irregularly,  0-10  .  . 
Feather  duster  prohibited,  no  dry  sweeping,  10 

Bubble  fountains,  10 

Has  adequate  play  space,  10;   inadequate,  0-.") 

Has  clean  drinking  water,  10 

Has  clean  toilets,  10 ;   unclean,  0-5    .... 
Outdoor  recreation  parks,  10 ;   none,  0  .     .     . 


Church :  Well  ventilated,  10  ;   badly,  0-5       .     . 
Heat  evenly  distributed,  10  ;   unevenly,  0-5 
Cleaned  regularly,  10  ;   irregularly,  0-5  .     . 

Without  carpets,  10 

Without  plush  seats,  10 


Streets:  Sewerage  underground,  20;   surface,  0-10 

No  pools  neglected,  10 

No  -garbage  piled  up,  10        

Swept  regularly,  20  ;   irregularly,  0-10   .... 

Sprinkled  and  flushed,  10 

Has  baskets  for  refuse,  10 

All  districts  equally  cleaned,  20 ;   unequally,  0-10 


Near-hy  Stores:  Clean,  10;  poorly  cleaned,  0-5 
Free  from  flies,  10 ;  partly,  0-5  .  .  .  . 
Food  screened,  10 ;  partly,  0-5  .  .  .  . 
Milk  used  in  bottles,  10  ;  dipped,  0  .  . 
Grade  goods  high,  10  ;   medium,  5-0      .     . 


Home:  Use  score  card  already  worked  out 
Multiply  total  by  2,  making  perfect  total 


Grand  total 


i    k.  i\r  r.i    i 


20 
20 
10 
10 
10 
10 
10 
10 


100 


10 
10 
10 
10 
10 


50 


20 
10 
10 
20 
10 
10 
_20_ 
100 


10 
10 
10 
10 
10 


50 


2U) 


.500 


ALL...V 


Conclusion.  —  Allowino-  200  as  l)acl,  250  as  poor.  :m  pas.^alde, 
350  fair,  400  good,  450  and  above  exceUent.  estimate  tlie  ccndi- 
tions  of  your  environment. 


28       ENVIRONMENT  OF  PLANTS  AND  ANIMALS 

Problem  5 :  To  determine  and  to  illustrate  hy  a  graph  the 
changes  of  temperature  {one  of  the  factoids  of  the  environmejit) 
during  a  given  day. 

Materials.  —  Thermometer,  clock,  graph  paper. 

Method  and  Observations.  —  Take  the  temperature  (outside) 
at  7  A.M.  and  at  each  successive  hour  during  the  day  until  6  p.m. 
On  a  piece  of  graph  paper  lay  off  a  line  parallel  to  the  bottom 
of  the  page.  On  this  line,  at  equal  distances,  place  your  hours, 
beginning  at  7  and  ending  at  6.  Then  from  the  line  made  as  a 
base,  erect  perpendiculars  on  each  of  the  hour  marks.  On  these 
perpendiculars  mark  the  record  of  the  thermometer  at  the  given 
hour.     Begin  your  record  at  the  base  line,  e.g.,  if  the  thermometer 


IXQ 

h 

50^ 

z 

— 

=  45 

40- 

- 

^ 

=  3S 

30^ 

= 

- 

=  25 

20- 

E 

^ 

-15_ 

—  f: 

- 

IIIIMI 

E  5 

o;E 

©a 

1 

m 


m^im 


so 


40 


30 


20  _ 


10 


o  I— I 

(51 


45 


33 


-ZS 


-15 


^ 


n 


(£iji[i]  ^ 


so 


40 


30 


zo 


lo 


45 


-35 


0  -  q 


2$ 


15 


SO 
40 

30 
20 


Hi 


10 


45 


35 


-25 


IS 


m 


PROBLEM  5 


29 


registers  50°  at  7  a.m.,  make  50  your  start- 
ing point  on  the  line,  and  if  the  thennoino- 
ter  has  risen  to  56°  at  8  o'clock,  then  count 
off  six  squares  on  your  graph  paper  ai)ove 
the  base  line.  Do  this  for  each  hour  in 
the  12  for  which  your  record  has  been 
made.  Connect  the  marks  made  on  the 
vertical  lines.  The  result  is  a  curve  like 
the  accompanying,  showing  the  tempera- 
ture record  of  the  day. 

Conclusion.  —  What  changes  take  place 
in  the  temperature  factor  of  a  given  day? 

NOTE.  —  Another  suggested  exercise  is:  Relation 
of  the  body  to  intake  of  water. 


n 

IT 

14 

ty 

n 
n 


;i 


: 


'■I: 


(9M<ltli       •I'<S« 


30       ENVIRONMENT   OF   PLANTS   AND   ANIMALS 

I^rohletn  (i :  To  make  a  graph  to  show  how  much  fluid  I  take 
into  my  body  in  a  day. 

Method  and  Observations.  —  Make  a  careful  estimate  of  the 
amount  of  water  drunk  by  glasses  or  cups  and  note  hours  when 
you  take  it.  Note  also  milk,  coffee,  tea,  soda,  etc.,  taken.  Make 
a  graph  to  show  when  and  how  much  fluid  passes  into  the  body  in 
24  hours. 

Is  this  graph  a  continuous  curve?     Explain. 

Note.  — Ability  to  make  and  to  understand  graphs  is  something  that  every  well- 
educated  girl  and  boy  should  acquire.  The  above  exercises  are  suggested  as  easy 
data  for  making  two  different  graphs,  each  of  which  will  have  a  different  ap- 
pearance. Teachers  are  expected  to  give  the  class  data  from  which  other  graphs 
may  be  constructed. 

Problem  7 :  May  environment  influence  public  health  ? 

Method  and  Observations.  —  Study  the  following  table.  Look 
up  the  location  of  each  of  the  countries  and  cities.  Find  out  all 
you  can  about  their  climate,  housing  conditions,  location  and  con- 
dition of  water  supply,  etc. 

Death   Rate    per    10,000    Population,  Pneumonia   and   Bronchitis, 

Five-Year  Period  1896-1900 

England  and  Wales 22.70 

Scotland 27.40 

Stockhohn 26.70 

London 31.20 

Berlin 16.10 

Vienna 39.70 

Christiania 21.30 

Boston 30.60 

Chicago 24.20 

Philadelphia 25.10 

New  York  city 36.60 

Might  any  factors,  such  as  climate,  slums,  overcrowding,  etc., 
have  an  effect  upon  the  death  rate? 

Conclusion.  —  What  factors  may  influence  the  death  rate? 


REFERENCE   BOOKS  31 


Problem  Questions 

1.  What  is  meant  by  environment?     Give  examples  for  a  plant ; 
a  canary ;  a  cat ;  yourself. 

2.  How  might  a  given  factor  of  the  environment,  as  the  air,  be 
changed  in  yom^  home?     In  a  factory?     In  a  mine? 

3.  How  might  climate  affect  the  environment? 

4.  Your   school   is   an   important   part   of  your   (^nvirf)nmont. 
What  might  you  do  to  better  it? 

5.  What  is  a  graph?     Of  what  use  is  a  graph?     Kxi)lain. 

6.  Why 'should  every  well-educated  person  understand  graphs? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  II.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chaps.  II,  X.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chaps.  II,  XII.     American  Book  Company. 

Allen,  Civics  and  Health.     Ginn  and  Company. 

Bailey,   How  Plants   Live    Together.     Cornell    University  Nature   Study  Quarterly, 

No.  6,  October,  1900. 
Bergen  and  Davis,  Principles  of  Botany,  Chaps.  XXXVI,  XXX\'II.     Ginn  and 

Compa/iy. 
Caldwell  and  Eikenberry,  Elements  of  General  Science.     Ginn  and  Company. 
Clark,  An  Introduction  to  Science.     Araorican  Book  Company. 
Coulter,  Textbook  of  Botany,  Chaps.  XXI,  XXII,  XXIII,  XXIV.     D.  Appleton 

and  Company. 
Darwin,  Different  Forms  of  Flowers  on  Plants  of  the  Same  Species.     D.  Appleton 

and  Company. 
Hessler,  First  Year  of  Science.     Benj.  Sanborn  and  Company. 
Hough  and  Sedgwick,  Elements  of  Hygiene  and  Sanitation.     Ginn  and  Company. 
Jordan  and  Kellogg,  Animal  Life.     D.  Appleton  and  Company. 
Merriam,  Life  Zones  and  Crop  Zones  in  the  United  States.     U.  S.  Department  of 

Agriculture,   Bulletin   10. 
Sharpe,  Laboratory  Manual  in  Biology.     American  Book  Company. 
Warming,  Ecology  of  Plants,  and  Introduction  to  the  Study  of  Plant  (\)mmun{tia. 

Frowde,  Clarendon  Press,  London. 
Weed,  Wild  Flower  Families.     J.  B.  Lippincott  Company. 


III.   THE  INTERRELATIONS    OF  PLANTS   AND 

ANIMALS 

Problem,  —  To  discover  tJie  general  interrelations  of  green 
plants  and  animals. 

(a)  Plants  as  homes  for  insects. 

(b)  Plants  as  food  for  insects. 

(c)  Insects  as  pollirzating  agents. 

Laboratory  Suggestions 

A  field  trip.  —  Object :  to  collect  common  insects  and  study  their  general 
characteristics  ;  to  study  the  food  and  shelter  relations  of  plants  and  insects. 
The  pollination  of  flowers  should  also  be  carefully  studied  so  as  to  give 
the  pupil  a  general  \'iewpoint  as  an  introduction  to  the  study  of  biology. 

Laboratory  exercise.  —  Examination  of  simple  insect,  identification  of 
parts  —  drawing.  Examination  and  identification  of  some  orders  of 
insects. 

Laboratory  demonstration.  —  Life  history  of  monarch  and  some  other 
butterflies  or  moths. 

Laboratory  exercise.  —  Study  of  simple  flower  —  emphasis  on  work  of 
essential  organs,  drawing. 

Laboratory  exercise.  —  Study  of  mutual  adaptations  in  a  given  insect 
and  a  given  flower,  e.g.,  butter  and  eggs  and  bumblebee. 

Demonstration  of  examples  of  insect  pollination.  — -  Field  work  if  possible. 

To  THE  Teacher.  —  In  a  broad  way  this  chapter  may  be  used  to  show  the  in- 
terdependence of  organisms.  As  much  of  the  work  as  possible  should  be  made  to 
depend  upon  field  trips,  as  the  interest  thus  gained  carries  over  into  the  laboratory 
later.  Specifically,  emphasis  should  be  placed  on  the  accurate  determination  of 
relations  existing  between  a  given  insect  and  flower  as  in  cross  pollination.  For 
this  purpose  careful  study  should  be  made  of  some  one  flower  in  connection  with 
some  one  insect  that  is  known  to  act  as  a  pollinating  agent. 

To  the  city  child,  trips  to  the  parks  and  fields  are  especially  helpful  because 
they  set  right  his  reaction  to  the  term  "  environment. "  For  that  reason  especial 
emphasis  is  made  in  this  book,  a  civic  biology,  to  field  trips.  The  young  citizen 
should  see  a  reason  for  the  inclusion  of  vast  sums  in  a  city  budget  for  the  purchase 
and  maintenance  of  parks.  This  trip  should  indirectly  give  him  reasons  which 
later  will  justify  his  actions  as  a  taxpayer  and  a  citizen. 

32 


PROBLEM   S  33 

rroblem  S :    A  field  trip. 

Materials.  —  For  collecting  purposes  an  insect  net.  ci^ar  l.oxcs 
containing  sheets  of  cork,  insect  pins,  and  ;i  cyanide  bottle  are 
useful.  (Caution.  Do  not  smell  the  cyanide  ;  even  the  fumes  are 
deadly  poison.)  See  Comstock's  Insect  Life  for  good  (hrections 
how  to  make  nets,  cyanide  bottle,  and  coUecting  l)oxes. 

Note.  —  Read  these  directions  carefully  before  beKinninR  work. 
Object  of  trip  :   The  object  of  this  trip  is  threefold  : 

1.  To  find  out  some  of  the  relations  of  mutual  heli)  existing  l>etwcen  plants  and 
animals. 

2.  To  learn. to  know  a  few  common  insects,  and  to  collect  them  for  later  study. 

3.  To  have  such  an  enjoyable  time  that  you  will  wish  to  go  again  by  yourself. 

a.  Insects  and  Flowers 

Method  and  Observations.  —  Your  trip  should  include  fields  and 
waste  lots,  covered  with  weeds  and  trees.  Look  for  six-legged 
animals  (insects)  on  plants.  Do  they  receive  any  jirotection 
from  such  plants?  Shelter?  Food?  CJive  exami)les  under 
each  of  th'e  above  headings.  Do  you  find  any  insects  laying  their 
eggs  upon  plants?     Why  do  you  think  they  do  this? 

Follow  a  bee  until  it  alights  on  a  flower.  Try  to  hnd  out  exactly 
what  it  gets  from  the  flower,  and  how  it  does  it.  Now  observe 
where  it  goes  next.  Do  bees  visit  flowers  of  the  same  kind  in 
succession  ? 

What  are  your  conclusions  regarding  the  nuitual  relations  Ik?- 
tween  the  bee  and  the  flower?  Do  both  receive  benefit?  Write 
your  answer  on  paper  supplied  by  your  instructor. 

Look  for  other  flying  insects  that  are  on  flowers.  Extra  credit 
is  given  for  the  working  out  of  the  relation  between  a  buttertl\- 
and  a  flower. 

Carefully  observe  the  goldenrod  blossoms  tor  \ellow  and  black 
beetles  (locust  borer)  about  1  inch  long.  Does  the  be(>tle  get  any 
good  from  the  plant?  Might  it  give  the  plant  aiiythiiig  in  return? 
Write  a  paragraph  on  this. 

Observe  grasshoppers  or  other  insects  on  stalks  of  gra.<s.  ^^  li.it 
are  they  doing  there?  Do  they  give  any  return  to  the  i)lant  ? 
Write  a  paragraph  on  this  relation. 

HUNTER   LAB.   PROB. — 3 


U    INTERRELATIONS   OF   PLANTS   AND   ANIMALS 

b.   Collections 

Method  and  Observations.  —  Collect  as  many  different  sorts  of 
insects  as  possible  and  bring  them  to  your  instructor,  who  will 
help  you  name  your  specimens.  You  will  study  these  specimens  in 
detail  when  you  return  to  school,  so  be  careful  not  to  injure  them. 

Prohletn  9 :  How  to  hnow  an  insect. 

Materials.  —  Any  living  or  dead  insect,  bee,  butterfly,  or  grass- 
hopper preferred.     Hand  lens. 

Method.  — Carefully  examine  any  insect. 

Observations.  —  Notice  that  the  body  is  divided  into  three 
regions :  the  head;  a  middle  part,  the  thorax;  and  a  hind  part, 
the  abdomen.  (See  Figs.,  pp.  29,  30,  Civic  Biology.)  These  parts 
are  further  divided  into  joints  {segments).  Look  at  the  head. 
Find  the  feelers  {antennae),  the  large  compound  eyes,  and  certain 
movable  mouth  parts.  What  do  you  find  attached  to  the  thorax  ? 
How  many  pairs?  Look  carefully  along  the  sides  of  the  abdo- 
men for  very  tiny  breathing  holes  {spiracles) .  All  insects  breathe 
by  a  system  of  air  tubes  {trachece)  opening  along  the  sides  of  the 
body.  The  characters  you  have  just  found  should  enable  you  to 
distinguish  an  insect  from  all  other  animals. 

Conclusion.  —  1 .  Write  a  paragraph  telling  what  structural  char- 
acters an  insect  has. 

2.  Make  a  drawing  of  an  insect  to  show  all  the  parts  that  we 
have  seen  above.     Label  each  part. 

Problem  10:  To  leam  to  recognize  insects  that  frequent 
floivertng  plants. 

Method.  —  This  work  may  best  be  taken  on  a  field  trip,  although 
laboratory  work  from  boxes  containing  mounted  insects  of  differ- 
ent groups  may  well  be  substituted. 

Note.  —  insects  have  been  shown  to  be  animals  that  have  three  jointed  parts  to 
the  body,  three  pairs  of  jointed  legs,  feelers,  compound  eyes,  and  a  more  or  less  hard 
skeleton  on  the  outside  of  the  body.  They  may  or  may  not  have  wings.  They 
breathe  through  a  system  of  air  tubes  called  trachece. 

The  following  orders  or  groups  of  insects  are  likely  to  be  found 
feeding  or  living  upon  flowering  plants.     The  position  and  kind 


PROBLEM    10 


35 


of  wings  and  the  kind  of  mouth  parts  ui-c 
the  guides  by  which  we  know  the  ordcr.s  of 
insects. 

Bees  and  Wasps  {Hymenoptera,  mem- 
brane wings).  —  The  wings  are  gauzy  and 
four  in  number.     These  insects  have  stings 


t    \ 


(look  at  the  end  of  the 
abdomen).  The  moutli 
l)arts  are  Um  comph- 
catcd  for  a  beginner  to 
use  for  identification. 

Butterflies  and 
Moths  {Lepidoptera, 
scale  wings).  —  Char- 
acterized by  having  two 
pairs  of  large  wings, 
covered  with  t  i  ny 
bright -('()l()r('(l  scales. 
Head  j)r()vitled  witii  a 
long  ])roboscis  or  suck- 
ing tube  which  is  coiled 
up  when  at  rest. 

Grasshoppers  (Or- 
t  li  <>  /)  1 1,  ra,        straight 


wings).  —  Found  on  most  green  weeds.  The 
mouth  parts  are  fitted  fnv  biting.  Hind  wings, 
if  present,  are  foldcMl  uj)  lengthwise  undiM-  the 
outer  wings  when  at  rest. 

FHes  (/)/>/r/v/,  two  wings).  —  Usually  small 
insects  with  but  a  single  i)air  of  gauzy  wings. 
A  short  ):)r()boscis. 

Bugs  {Uciniptcra,  half  wings).— The  wings 


30     INTERRELATIONS   OF   PLANTS   AND  ANIMALS 


are  not  alone  sufficient  identification,  as  they 
may  or  may  not  be  present.  A  jointed  pro- 
boscis which   points 


backwards    is    the 
only  sure   means  of 
knowing  this  group. 

Beetles  (Coleoptera,  sheath  wings). — 
Characterized  by  having  a  strong  front  pair 
of  wings  called  elytra,  usually  covering  the 
hind  wings  and  always  meeting  in  a  straight 
line  down  the  middle  of  the  back.  Mouth 
parts  hard,  pincher-like  jaws. 


a.  Field  Work 

Method.  —  Collect  as  many  different  kinds  of  insects  as  you 
can,  making  careful  notes  as  to  the  locality  where  the  insect  was 
found,  the  flowers  which  it  frequents,  the  kind  of  food  it  was  tak- 
ing from  the  flower,  and  the  order  to  which  it  belongs. 


b.  Laboratory  Work 

Observations.  —  From  boxes  containing  a  number  of  different 
insects  pick  out  one  from  each  order  given  above  and  give  your 
reasons  for  placing  that  particular  insect  in  the  order  which  you 
have  chosen  for  it. 

Conclusion.  —  1.  Why  do  certain  insects  always  frequent 
certain  flowers?  Look  at  the  insect,  especially  the  mouth  parts, 
ver3^  carefully  and  study  the  form  of  the  flower  before  making  your 
decision. 

2.  How  would  you  pick  out  (a)  a  bee,  (6)  a  butterfly,  (c)  a  bug, 
(d)  a  grasshopper  from  the  above  insects? 


Problem  11 

an  insect. 


To  study  the  life  history  {jnetamorphosis)  of 


Note.  —  Field  work  may  be  done  at  a  museum,  or  questions  may  be  worked  out 
from  some  of  the  excellent  preparations  made  by  the  Kny-Scheerer  Company  or 
other  of  the  biological  supply  houses. 


PR01U.EM    11  ;i7 

a.  Eggs 

Method  and  Observations.  —  In  the  field  look  on  the  inidcr  side 
of  leaves  for  tiny  ovoid  structures  {('(jy.s)  of  mot hs  Mrid  hiitlerfiies. 
The  eggs  of  the  cabbage  butterfly  may  be  found  at  almost  any 
time  on  the  under  side  of  cabbage  leaves. 

Conclusion.  —  Why  are  the  eggs  laid  on  the  //.////tr  side  of 
certain  leaves? 

b.   Larva  or  Caterpillar 

Observatipns.  —  Note  that,  besides  true  jointed  logs,  tlu^ 
caterpillar  has  others  called  prolegs.  Ht)\v  many  true  legs  ar(» 
there  and  where  are  they  located?     How  many  prologs  are  there? 

Locate  the  spiracles  or  breathing  holes.  Remember  wlicre 
they  are  located  on  an  adult  insect. 

Watch  the  caterpillar  when  it  feeds.  AVhat  kind  of  mouth 
parts  does  it  have?     Might  it  do  damage  to  plants?     How".' 

Conclusion.  —  1.  Is  a  caterpillar  a  worm?  (Look  in  your  bi- 
ology for  the  characteristics  of  worms.) 

2.  How  might  the  larvae  of  moths  or  butterflies  l)e  of  economic 

importance  ? 

c.  Pupa 

Materials.  —  Cocoons  of  several  species  of  moths  with  twigs  or 
other  parts  attached  should  be  furnished  for  this  exercise. 

Note.  —  Moths  spin  a  cocoon  for  themselves  at  this  stage.  Huttcrflics  spin  no 
cocoon  but  form  a  chrysalis. 

Observations.  —  Where  do  you  find  the  cocoon  or  chry.salis? 

Of  what  does  the  cocoon  seem  to  be  compo.sed?  (Tlie  cocoon  of 
the  Cecropia  is  excellent  for  this  purpose.) 

In  a  chrysalis  locate  by  means  of  the  body  markings  the  head, 
antennae  or  feelers,  eyes,  wings,  legs,  and  spiracles.  Are  all  the 
parts  of  an  adult  present? 

Open  a  cocoon.  What  do  you  find  insid(^'.'  Hnw  do  you  explain 
this? 

Conclusion. —  Making  use  of  all  the  knowledge  you  have 
gained,  write  a  brief  description  of  the  i)ui)al  stage  of  an  in.sect  and 
tell  of  what  use  this  stage  might  be  to  the  insect.  KcMiiember 
where  you  find  these  stages. 


38     INTERRELATIONS   OF   PLANTS   AND   ANIMALS 

d.   Adult  or  Imago 

Method.  —  Examine  carefully  an  adult  Initterfly  or  moth. 
Observations.  —  How  many  body  regions  has  it?     How  many 
legs  ?     Wings  ?     Antennae  ? 

How  does  this  stage  differ  from  the  pupal  stage? 

Note.  —  All  the  changes  undergone  by  an  animal  from  the  time  it  leaves  the 
egg  to  the  time  it  becomes  an  adult  are  known  as  the  stages  of  metamorphosis  of 
that  animal.  If  no  great  changes  in  form  occur,  then  the  animal  is  said  to  have 
an  incomplete  or  direct  metamorphosis.  But  if  changes  in  form  such  as  we  have 
just  seen  occur,  then  the  animal  is  said  to  pass  through  a  complete  or  indirect 
metamorphosis. 

Conclusion.  —  1.  What  insects  that  you  have  studied  pass 
through  a  direct  metamorphosis?     An  indirect  metamorphosis? 

2.  If  time  permits,  drawings  might  be  made  to  illustrate  the  life 
history  (metamorphosis)  of  a  moth  or  a  butterfly. 

Problem  12:  To  learn  the  structure  and  worh  of  the  parts  of 
a  flower. 

Materials.  —  Any  large  flower,  as  the  tulip  in  the  spring,  or  eve- 
ning primrose  or  gladiolus  in  the  fall. 

Method.  —  Carefully  examine  the  parts  of  a  flower. 

Note.  —  Flowers  are  built  so  that  the  parts  are  arranged  in  circles.  In  regular 
flowers  the  same  number  of  parts  (or  multiples  of  these  parts)  will  be  found  in  each 
circle. 

Observations.^ — How  many  parts  in  the  outermost  circle? 
These  parts  are  called  sepals.  Collectively  they  make  up  the 
calyx.  What  color  have  the  sepals?  In  a  young  flower  what 
seems  to  be  their  use  ? 

The  next  circle  of  parts  is  called  the  petals.  How  many  are 
there?  What  color  do  they  have?  Together  they  form  the 
corolla. 

The  little  knobbed  organs  are  called  stamens;  the  stalk  is  the 
filament,  the  knob  the  anther.  Describe  what  you  find  in  the 
anthers.  This  is  the  pollen.  Can  you  determine  how  it  gets  out 
of  the  anthers?     Use  a  hand  lens. 

In  the  center  of  the  flower  is  the  pistil.^     Describe  it.     The 

1  If  the  pistil  is  made  up  of  a  number  of  separate  parts,  each  part  is  called  a  carpel. 


PROBLEM    13 


39 


Part  Gf 

Color 

Slicipe      Use. 

Petal 

Sepal 

Starrven 

Pistil 

enlarged  part  at  the  base  (not  always  easily  seen;  is  the  uvanj; 
the  stalk  is  the  style;  the  tip,  which  is  sticky,  is  called  the  Hlif^mn. 
On  this  sticky  surface  pollen  grains  will  grow.  IIow  \\<\si\\\  pollen 
get  to  the  stigma? 

Cut  a  cross  section  through  the  ovanj.  Describe  what  you  find 
inside.  These  little 
structures  are  called 
ovules.  Under  cer- 
tain conditions,  which 
we  will  later  discuss, 
a  part  of  a  pollen 
grain  will  cause  these 
ovules  to  grow  into 
seeds. 

Fill  out  a  diagram 
like  the  accompany- 
ing in  yoiir  notebook. 

Conclusion.  —  1.  What  parts  of  the  flower  are  essential  for  tlic 
production  of  seeds? 

2.  What  are  then  the  essential  organs  of  a  flower? 

Drawings.  —  1.  A  flower  from  above.     Label  all  parts. 

2.  A  stamen,  showing  all  parts. 

3.  A  pistil,  showing  all  parts. 

Problem  13:  The  cross-pollination  of  Jhnrrrs. 

Method.  —  Take  a  trip  to  a  locality  wlicrc  flowers  are  a])uri(iant 
and  make  a  preliminary  study  of  the  relation  of  in.^ccts  to  flowers. 

Observations.  —  Notice  whether  the  flowers  are  being  visited 
by  insects. 

To  what  orders  do  these  insects  belong? 

Do  bees  visit  flowers  of  one  sort  in  succession,  or  of  dilTerent 
sorts?  Make  a  careful  study  of  this  point  by  following  a  .single 
bee  or  other  insect.     AVork  this  out  in  tlie  case  of  a  butterfly. 

Do  insects  seem  to  prefer  any  one  color  in  flowers  to  another 
color?     Make  careful  o])servations  on  this  i)oini. 

Can  you  discover  any  means  by  which  the  flower  iniiiht  affraef 
an  insect?     Remember  insects  can  probably  smell  and  taste  a.s 


40     INTERRELATIONS   OF  PLANTS   AND   ANIMALS 

well  as  see.     Might  the  shape  of  a  flower  be  of  use  to  an  insect? 
How? 

Conclusion.  —  L  What  do  insects  get  from  flowers? 

2.  What  kinds  of  flowers  do  they  frequent  most? 

3.  What  do  insects  give  to  flowers?  ' 

Problem  14:  To  study  cross-pollination  in  butter  and  eg^s. 

Note.  —  in  the  fall  of  the  year  one  of  the  best  flowers  for  study  is  found  in  the 
yellow  butter  and  eggs  {Linaria  vulgaris)  found  in  vacant  lots  and  along  roadsides. 
Any  cultivated  forms  of  the  toadflax  family  are  useful  for  this  purpose. 

Materials.  —  Butter  and  eggs  or  other  member  of  the  toadflax 
family,  bumblebees  in  formalin,  needle,  hand  lens.  (Diagrams, 
p.  39,  Civic  Biology.) 

Method.  —  Study  carefully  the  structure  of  butter  and  eggs 
for  any  adaptations  or  fitness  in  structure :  (1)  to  receive  insect 
visitors ;   (2)  to  effect  self-  or  cross-pollination. 

Observations.  —  Note  the  shape  of  the  flower.  Are  all  its 
petals  and  sepals  regular  (the  same  size  and  shape)  ?  Might  the 
shape  of  the  flower  offer  any  place  for  an  insect  (as  a  bee)  to 
light?  Try  it  with  a  bee.  What  would  happen  when  the  body 
of  the  bee  rested  on  the  lower  lip  of  the  flower  ?  Press  down  this 
lower  lip  and  look  inside  the  flower  for  the  stamens  and  pistil. 
What  is  there  peculiar  about  the  position  of  the  stamens  ?  Hold 
the  flower  in  a  natural  position.  Could  pollen  from  the  stamens 
reach  the  pistil? 

Examine  with  hand  lens  the  sides,  back,  legs,  and  head  of  a 
bumblebee.  What  do  you  find?  Now  push  the  body  of  the 
bee  into  an  open  flower.  (Remember  that  the  nectar  the  bee 
seeks  is  held  in  the  spur,  or  pointed  projection,  of  the  flower.) 
Over  what  structures  would  the  head  and  back  of  the  bee  rub? 
If  the  bee  visited  another  flower  of  the  same  sort,  what  would 
happen  ? 

Conclusion.  —  1.  How  is  the  butter  and  eggs  fitted  to  receive 
insect  visitors? 

2.  What  kind  of  pollination  is  most  common  in  butter  and  eggs? 
How  is  it  brought  about? 

3.  Explain  a  second  method  of  pollination  in  butter  and  eggs. 


PROBLEM   15  11 

4.  Make  a  drawing  (diagram)  to  show  liow  a  bee  liclps  to 
pollinate  butter  and  eggs. 

Prohlem  15 :  Special  directions  for  the  study  of  some  fall 

flowers.    (Extra.)  i 

The  Evening  Primrose  (Onagra  bienriis).  —  The  liabitat  pre- 
ferred by  this  flower  is  dry  fields,  roadsides,  or  waste  places.  The 
yellow  flowers  are  found  in  long,  upright,  densely  crowded  chisters. 
A  flower  cluster  in  which  the  indivickial  flowers  have  no  flower 
stalks  or  pedicles,  with  one  main  axis  to  the  cluster,  is  called  a  sjyike. 
Notice  that  young  and  old  flowers  and  fruits  are  all  on  the  same 
cluster.  Where  are  the  youngest  flowers  located  in  llic  cluster? 
Is  there  any  flower  at  the  end  of  the  main  stalk  ?  Could  you  deter- 
mine in  advance  the  length  of  the  flower  cluster?  Such  a  cluster 
is  said  to  be  indeterminate.  Why?  Study  a  single  open  flower. 
Note  the^calyx  and  corolla.  Are  the  parts  distinct?  How  many 
petals  do  you  find?  Notice  that  there  are  eight  stamens  and  that 
the  stigma  is  four-parted.  Cut  the  ovary  in  cross  section,  and 
see  how  many  locules  (spaces)  there  are. 

When  a  flower  has  each  circle  of  parts,  as  the  sepals,  petals, 
stamens,  and  pistils,  made  up  of  a  certain  number  of  divisions,  or 
when  they  appear  in  multiples  of  that  number,  the  flower  is  said 
to  be  symmetrical.  Here  we  see  a  very  striking  example  of  sym- 
metry in  a  flower. 

The  chief  attraction  to  insects  is  the  nectar,  which  is  formed  in 
nectar  glands  at  the  base  inside  the  slender  tubular  corolla.  In- 
formation is  given  to  the  insects  of  the  contents  by  a  faint,  sweet 
odor.  This  flower  is  not  visited  by  many  day-flying  in.^^cts. 
Can  you  determine  the  names  of  any  that  do  come  by  day?  At 
night  the  flower  opens  more  widely  and  the  scent  becomes  much 

iTo  THE  Teacher.  —  If  the  work  on  flowers  is  taken  up  in  (he  sprint:,  field  work 
should  result  in  the  collection  of  jack-in-the-pulpit,  oak.  wilh)w.  skunk  cahhaKo. 
grasses,  and  also  many  wild  flowers  which  show  special  achiptations  for  cross-polli- 
nation. In  the  fall  butterfly  weed,  Salvia,  turtlehead.  and  various  comi>ositC8 
show  wonderful  adaptation.  Original  investigation  on  simple  i)rohloms  of  thi.** 
kind  have  been  found  by  the  writer  to  he  the  best  means  of  stimul.ating  certain 
better  prepared  students  to  take  an  abiding  interest  in  this  work.  Two  or  thrcr 
sample  investigations  are  given  here  that  might  be  used  by  the  student  Jis  a  form  in 
jnaking  reports  on  other  flowers. 


42     INTERRELATIONS   OF  PLANTS   AND  ANIMALS 

more  noticeable.  Moths  are  its  chief  night  visitors.  The  long 
proboscis  is  thrust  into  the  flower  and  quickly  withdrawn,  but 
usuall}^  a  little  pollen  is  carried  off  on  the  palps  (projections  on  the 
sides  of  the  head).     This  may  be  left  on  the  next  flower  visited. 

Try  to  determine  what  other  insects,  if  any,  visit  the  evening 
primrose  at  night. 

Draw  a  single  flower  split  open  lengthwise  to  show  the  position 
of  the  parts,  and  especially  any  adaptations  to  insect  pollination. 
Look  for  any  special  means  for  the  prevention  of  self-pollination. 
Label  all  the  parts. 

Moth  Mullein  {Verhascum  blattaria).  —  The  moth  mullein  is 
one  of  the  most  beautiful  weeds,  despite  the  fact  that  few  blos- 
soms are  found  at  any  given  time.  The  plant  flourishes  on  dry, 
waste  land,  roadsides,  and  open  fields.  It  w-as  introduced  into 
this  country  and  has  since  become  common  here  and  in  Canada. 

The  flowers  are  found  in  a  long,  loose  raceme.  A  raceme  is 
like  a  spike,  except  that  each  flower  has  its  own  flower  stalk  devel- 
oped. Has  this  cluster  yellow  or  white  flowers  ?  Into  how  many 
parts  is  the  calyx  divided  ?  The  corolla  ?  Is  the  corolla  perfectly 
regular?  Notice  the  five  stamens.  Is  there  anything  peculiar 
about  the  filaments  ?  Are  they  all  of  the  same  length  ?  In  spite 
of  the  fact  that  the  flower  is  called  moth  mullein,  it  is  not  polli- 
nated to  any  extent  by  moths.  Bees  and  flies  are  the  chief  pollen 
bearers.  Bees  which  alight  on  this  flower  do  so  for  the  purpose 
of  collecting  pollen.  This  they  usually  gather  from  the  short 
stamens,  while  they  cling  to  the  longer  ones.  As  the  bee  lights  on 
another  flower,  the  pollen  on  the  under  side  of  the  body  is  trans- 
ferred to  the  stigma  of  this  flower. 

Draw  the  flower  from  above,  twice  natural  size. 

Jewelweed  {Impatiens  hiflora).  —  One  of  the  most  prevalent 
of  all  our  brookside  flowers  is  the  jewelweed.  It  well  deserves  its 
name,  a  pendant  flaming  jewel  of  orange. 

This  flower  is  very  irregular  in  shape.  Are  the  flowers  single 
or  in  clusters?  The  sepals  as  well  as  the  petals  are  colored.  The 
former  are  three  in  number,  one  of  which  is  sacklike  in  shape  and 
contracted  at  one  end  into  a  spur.  The  petals  are  also  three  in 
number.     Open  the  flower.     Notice  how  short  the  filaments  of 


PROBLEM    H> 


l:i 


the  five  stamens  are.  Make  a  note  of  Ihcir  position  with  relation 
to  the  pistil.     Would  self-pollination  he  possible  in  tiiis  (lower? 

If  it  is  possible  to  study  jewelweed  out  of  doors  in  its  native 
habitat,  it  will  be  found  that  hunnnin^-  birds  are  tlie  visitors 
which  seem  best  adapted  to  cross-pollinate  the  flower.  A  care- 
ful series  of  observations  by  some  girl  or  boy  upon  the  cross- 
pollination  of  this  flower  might  add  much  to  our  knowledge 
regarding  it. 

Jewelweed  has  the  habit  of  producing  (usually  in  the  fall) 
inconspicuous  flowers  which  never  open  but  which  produce  .seeds 
capable  of  germination  and  growth.  vSuch  flowers  are  said  to  be 
cleistogamous.  In  England,  where  the  plant  has  been  introduced, 
it  is  found  to  produce  more  cleistogamous  flowers  than  showy  ones, 
and  the  showy  ones  do  not  produce  seed.  There  are  no  humming 
birds  in  /England,  and  without  this  means  of  pollination,  the 
cleistogamous  form  prevails. 

Make  a  front-view  drawing  of  the  flower  of  jewelweed  twice 
natural  size. 


Proble^n  16:  To  find  other  poUinating  agents  besides  inserts. 

Materials  and  Method.  —  Study  as  many  other  llowers  as 
possible,  using  Kny  or  other  charts  and  books  of  reference  to  help 
in  your  work.  Suggested  for  this  are  various  types  of  orchids 
(described  and  pictured  by  Charles  Darwin),  turtlehead,  Sulria, 
and  others  previously  mentioned. 

Observations.  —  Look  for  any  peculiarities  of  structure  that 
seem  to  be  for  purposes  of  pollination.  Explain.  If  j)ossible, 
study  especially  the  structure  of  the  flowers  of  sagi\  pea  or  bean, 
and  butterfly  weed. 

Find  out  how  pol- 
lination is  accom- 
plished in  the  corn 
plant ;  in  the  pines 
and  grasses.  Read- 
ing as  well  as  field 
work  wdll  help  here. 
Are  stamens  and  pis- 


Polliivatibrv. 

E^TCCVTXVpleS 

iTx^ects 

^v>^iiva 

Vv^cit  ei' 

OtKer  Adeixt^ 

44     INTERRELATIONS   OF   PLANTS   AND   ANIMALS 

tils  ever  separated  by  being  on  different  plants?     Give  examples. 
ExpLain. 

Conclusion.  —  Using  a  form  like  that  on  page  43,  tabulate  the 
various  ways  in  which  pollination  is  brought  about. 

Problem  Questions 

1.  What  relation  might  insects  and  plants  have  to  each  other? 
Is  this  relation  always  a  useful  one? 

2.  How  could  you  tell  an  insect  from  other  animals? 

3.  How  could  you  tell  a  bee,  butterfly,  bug,  grasshopper,  beetle? 

4.  What  is  meant  by  metamorphosis? 

5.  Of  what  use  might  metamorphosis  be  to  an  insect? 

6.  Which  is  the  most  beneficial  stage  of  the  metamorphosis  of  a 
moth  or  a  butterfly?     The  most  harmful  stage?     Why? 

7.  Of  what  use  to  a  flower  are  its  sepals,  petals,  stamens,  pistil? 

8.  What  parts  could  a  flower  do  without?     Why? 

9.  What  do  insects  get  from  flowers?  What  do  they  do  with 
what  they  get  ? 

10.  Is  pollination  intended  by  an  insect? 

11.  What  do  we  mean  by  an  adaptation  f    Illustrate  from  a  flower. 

12.  What  do  we  mean  by  a  wiiiitaZ  adaptation  ?  Illustrate  from 
a  flower  and  an  insect. 

13.  What  adaptations  are  found  in  flowers  to  prevent  self- 
pollination?     Give  examples. 

14.  What  agents  other  than  insects  might  transfer  pollen? 

15.  Compare  with  your  own  environment  the  environment 
which  you  have  found  animals  and  plants  to  have  in  the  park. 
How  are  the  two  environments  alike  and  how  do  they  differ? 

16.  What  constitutes  an  artificial  environment?  A  natural 
environment  ? 

17.  What  are  some  uses  to  you  of  a  city  park?  Do  not  look 
in  your  book  for  an  answer. 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  III.     American  Book  Company, 
Hunter,  Elements  of  Biology ,  Chap.  IV.     American  Book  Company. 
Hunter,  Essentials  of  Biology,  Chap.  IV.     American  Book  Company. 
Andrews,  Botany  All  the  Year  Round,  pp.  222-236.     American  Book  Company. 


REFERENCE  BOOKS  15 

Atkinson,  First  Studies  of  Plant  Life,  Chaps.  XXV-XXVI.     Ciiun  .-md  rorni>!iny. 

Bailey,  Crossing  of  Egg  Plants,  Bulletin  26,  Cornell  Exi)orinjcnt  SUition. 

Bailey,  Effect  of  Pollination  upon  Tomatoes,  Bulletin  2S,  ( 'ornoll  Kxperinient  Sta- 
tion. 

Bailey,  Philosophy  of  Crossing  Plants,  Considered  in  liifcrcncc  to  thrir  Imjtrorement 
under  Cultivation.     Report  of  Massachusetts  State  Board  <»f  A«rirulturo.  ls'j\. 

Bailey,  New  Ideals  in  the  Improvement  of  Plants.  Country  Life  in  America,  July, 
1903. 

Bailey,  Plant  Breeding.     The  Macmillan  Company. 

Bergen  and  Caldwell,  Practical  Botany,  Chap.  VIII.     Ginn  an«i  Conipany. 

Campbell,  Lectures  on  the  Evolution  of  Plants.     The  Macniilhin  Company. 

Coulter,  Plant  Life  and  Plant  Uses,  pp.  301-322.     American  liook  Cfjm|»:iriy. 

Coulter,  Plant  Studies,  Chap.  VII.     D.  Appleton  and  Company. 

Coulter,  Barnes,  and  Cowles,  A  Textbook  of  Botany,  Part  II.  .\mcriran  Book 
Company. 

Crosby,  School  Exercises  in  Plant  Production,  Farmers'  Bulletin  408,  U.  S.  Depart- 
ment of  Agriculture. 

Crosby  and  Howe,  School  Lessons  on  Corn,  Farmers'  Bulletin  409,  U.  S.  Depart- 
ment of  Agriculture. 

Dana,  How  to  Know  the  Wild  Flowers.     Scribner's  Sons. 

Dana,  Plants  and  Their  Children,  pp.  187-255.     American  Book  Company. 

Darwin,  Insectivorous  Plants.     D.  Appleton  and  Company. 

Darwin,  Different  Forms  of  Flowers  on  Plants  of  the  Same  Species.  I),  .\ppleton 
and  Company. 

Darwin,  Fertilization  in  the  Vegetable  Kingdom,  Chaps.  I  and  II.  D.  Appleton 
and  Company. 

Darwin,  Orchids  Fertilized  by  Insects.     D.  Appleton  and  Company. 

Darwin,  Cross  and  Self  Fertilization  in  the  Vegetable  Kingdom.  1).  .\ppleton  and 
Company. 

De  Vries,  Plant  Breeding.     Paul,  Kegan,  Trench,  Trubncr  and  Company.  London. 

East,  The  Rdle  of  Selection  in  Plant  Breeding.     Popular  Science  Monthly,  Aujfust, 

1910. 
Ely,  Color  Arrangement  of  Flowers.     Scribner's  Magazine,  March.  ISHO. 
Gibson,  My  Studio  Neighbors,  p.  227.     Harper  and  Brothers. 
Henderson,  Functions  of  an  Environment.     Science,  April   10,  r.>14. 
Howe,  How  to  Test  Seed  Corn  in  School.     Circular  96,  U.  S.  Departn.ont  of  Auri- 

culture. 
lies,  Teachiyig  Farmers'  Children  on  the  Ground.      World's  Work,  .M:i>  .   1«K«. 
Lubbock,  British  Wild  Flowers.     The  Macmillan  (  ompany. 
Lubbock,  Flowers,  Fruits,  and  Leaves,  Part  I.     The  Macmillan  Company. 
Lyle,  Plant  Breeding  in  a  Dutch  Garden.     Everybody's  Magazine,  .Tunc.  1902. 
Miiller,    The  Fertilization  of  Flowers.     The   Macmillan  Company. 
Needham,  General  Biology,  pp.  1-50.     The  Comstock  Publishing  Company. 
Newell,  A  Reader  in  Botany,  Part  II.  pp.  1-90.     Ginn  and  Company. 
Osterhout,  Experiments  ivith  Plants,  Chap.  VI.     The  Macmillan  Company. 
Parsons,    Children's   Gardens  for  Pleasure,    Health,   and   Education,     bturpis   and 

Walton. 
Sharpe,  A  Laboratory  Manual  in  Biology.     Ameri.-an  B.M.k  Company. 
Stack,  Wild  Flowers  Every  Child  Should  Know.     Doublcday.  Page  and  C  ompan>  . 


IV.   THE  FUNCTIONS  AND  COMPOSITION  OF  LIVING 

THINGS 

Problems.  —  To  discover  the  functions  of  living  matter. 
(a)   In  a  living  plant. 
(,b)  In  a  living  animal. 

Laboratory  Suggestions 

Laboratory  study  of  a  living  plant.  —  Any  whole  plant  may  be  used ; 
a  weed  is  preferable. 

Laboratory  demonstration  or  home  study.  —  The  functions  of  a  living 
animal. 

Demonstration.  —  The  growth  of  pollen  tubes. 

Laboratory  exercise.  —  The  growth  of  the  mature  ovary  into  the  fruit, 
e.g.,  bean  or  pea  pod. 

To  THE  Teacher.  —  The  object  of  this  chapter  is  first  to  give  the  child  a  pre- 
liminary or  pre-view  of  the  larger  problem  outlined  in  the  six  following  chapters, 
i.e.,  plant  growth  and  nutrition.  Then  the  concept  of  the  cell  as  a  unit  of  structure 
should  be  worked  out  and  the  very  important  notion  of  fertilization  in  its  relation 
to  the  development  of  the  plant.  Problems  17,  18,  19,  and  20  might  well  follow 
Chapter  II,  if  the  teacher  desires,  and  the  problems  on  fertilization  introduced  after 
that  of  the  structure  of  the  flower.  Experience  has  shown  the  sequence  here 
followed,  however,  to  work  out  well. 

Any  simple  plant  or  animal  tissue  can  be  used  to  demonstrate  the  cell.  Epider- 
mal cells  may  be  stripped  from  the  body  of  the  frog  or  obtained  by  scraping  the 
inside  of  one's  mouth.  The  thin  skin  from  an  onion  stained  with  tincture  of  iodine 
shows  well,  as  do  thin  cross  sections  of  a  young  stem,  as  the  bean  or  pea.  One  of  the 
best  places  to  study  a  tissue  and  the  cells  of  which  it  is  composed  is  in  the  leaf  of  a 
green  water  plant,  Elodea.  In  this  plant  the  cells  are  large,  and  not  only  their  out- 
line, but  the  movement  of  the  living  matter  within  the  cells,  may  easily  be  seen,  and 
the  parts  described  in  the  next  problem  can  be  demonstrated. 

Problem  1 7 :  The  uses  of  the  parts  of  a  plant. 
Materials.  —  Growing  plants,  seedlings,  and  red  ink. 

NOTE.  —  A  growing  plant  has  roots,  stems,  leaves,  flowers,  and  fruits. 

Method  and  Observations.  —  Locate  each  part  in  the  specimen 
before  you.     If  you  water  a  growing  plant  that  is  badly  wilted, 

4G 


PUOBLEAl    18 


47 


what  happens?  What  would  one  use  of  llic  roots  he?  W  liat 
holds  a  plant  iii  the  ground?  In  seedhn^s  the  roots  of  whifli 
have  been  placed  in  red  ink  note  carefully  the  appearance  of  root, 
stem,  and  leaves.  Note  that  the  rod  fluid  extends  into  the  leaves. 
How  did  it  get  there?     What  is  one  use  of  the  stem  to  (he  plant? 

Examine  a  piece  of  sugar  cane,  a  stem.  Taste  it.  What  does 
it  contain?     What  might  another  use  of  stems  he? 

Examine  leaves  which  are  in  a  sunny  window.  How  arc  (hey 
placed  with  reference  to  the  light?  Later  we  will  find  tha(  green 
leaves  make  food  for  the  plant  when  in  the  sunligiit. 

We  have  seen  flowers,  and  found  that  in  time  they  form  fruits. 
Fruits  in  turn  hold  the 
seeds  which  give  rise 
to  new  plants. 

Conclusion.  —  1. 
Write  a  short  compo- 
sition on  the  uses  of 
all  of  its  parts  to  a 
green  plant. 

2.  Fill  in  a  table  hke 
the  accompanying. 

Problem  IS:  To  study  the  needs  and  use.^  of  fhr  jinrf'^  of  a 
living  animal. 

Method.  —  Study  your  pet  cat  or  dog.  Make  a  list  of  all  (he 
things  that  your  pet  requires  in  order  to  live.  Classify  tlu^  intake 
of  the  pet  under  the  headings,  Food,  Water,  Air,  etc. 

What  parts  of  the  body  have  to  do  with  taking  in  food ".'  Water? 
Air?  When  a  structure  has  a  work  to  do,  we  call  (ha(  work  its 
function.  What  other  functions  has  your  pet  besiik\s  tho«'  ahi-ady 
mentioned?     (Your  teacher  will  helj:)  you  here.) 

Conclusion.  — What  are  the  needs  and  what  arc  th(»  functions 
of  a  living  animal?  How  do  you  think  they  compare  wi(h  those 
of  a  plant? 

STUDY   OF   COMPOUXD    MirilOSCOPE 
1.    NOTE. —  The  microscope,  an  instrument  for  makinn  .•^n.all  ohjort,s  ai.i>oar 
larger,  comprises  two  parts:    the  stand  (A.  B.  C)  an<l  the  lon.sea  (F.  G). 


Petri   of 
Plciivt 

Use  to  Plant 

Use    to    r^an 

Root 

O  teixv 

Leaves 

Flo^ver 

48 


FUNCTIONS   OF   LIVING   THINGS 


2.  NOTE. — The  stand  consists  of  the  following  parts:  base  (A),  pillar  (B), 
stage  (M),  arm  (C),  tube  (D),  diaphragm  (S),  mirror  (O),  revolving  nose  piece  (E), 
the  coarse  (K)  and  the  fine  (L)  adjustment. 


Of  what  material  is  the  stand  made?  What  are  the  advantages  of  using  such 
material  ? 

3.    NOTE.  —  The  stand  rests  upon  a  broad  base  or  foot. 

What  is  the  shape  of  the  base?  Why  should  the  base  be  broad  and 
heavy  ? 


PROBLEM    [[)  40 

4.  NOTE.  —  The  jointed,  vertiral  pillar  Rives  attachment  to  the  arm.  H.ipj.i.rt- 
ing  the  main  tube  of  the  instrument. 

What  are  the  advantage.s  of  having  the  pilhir  jointed? 

5.  NOTE.  —  Extending  forward  from  the  pillar  below  (he  arm  is  fho  HtaKc  on 
which  is  placed  the  object  to  be  examined. 

Describe  the  location  of  the  perforation  in  (he  stage.  Wliat  i.s  ius  um''.'  Wh.ii 
is  the  use  of  the  revolving  wheel,  or  diaphragm,  pivoted  to  tlie  .stage? 

G.  NOTE. —  Below  the  stage  is  a  movable  bar  (P),  carrying  the  mirrors  or 
reflectors. 

In  how  many  different  directions  can  you  move  the  mirrors?  What  i.s  tho 
advantage  of  havi<ig  them  movable?  What  kind  of  surface  d(.  the  mirrors  rcs[>ec- 
tively  show?     What  is  the  use  of  the  mirrors? 

7.  NOTE.  —  A  hollow  cylinder  containing  two  lenses  fits  into  the  upper 
end  of  the  tube.     It  is  called  the  eyepiece  or  ocular.  (G). 

Why  is  the  name  eyepiece  applied? 

8.  NOTE.  —  Small  brass  mounts,  each  containing  several  lenses,  are  attached 
to  the  tube  at  its  lower  end;    they  are  the  object  lenses  or  objectives  (F,  F). 

Why  is  the  name  objective  given  to  these  lenses?  How  many  objective.s  arc 
there  in  your  microscope? 

9.  NOTE.  —  The  low  power  (a  slightly  magnifying  objective)  has  a  .short  and 
broad  mount.     The  high-power  objective  has  a  long  and  narrow  mount. 

What  fractional  numbers  do  you  find  on  the  mount  of  the  high  an<l  the  low 
power  objectives,  respectively? 

10.  Note.  —  The  objectives  are  attached  to  a  revolving  device,  the  nose  piece. 
What  are  tTie  advantages  of  a  revolving  nose  piece? 

11.  Note.  —  To  obtain  a  clear  image  of  the  object  under  examination,  we  must 
be  able  to  vary  the  distance  between  the  lenses  and  the  object ;  that  is.  to  focus 
the  instrument.  The  microscope  is  brought  into  focus  by  slightly  turning  either 
of  the  large  wheels  placed  at  the  top  of  the  arm  near  the  tulK*. 

Why  are  these  wheels  called  the  coarse  adjustment?  (Turn  one  of  them  gently  !) 
W^hat  movement  results? 

12.  NOTE. —  The  milled  head  of  the  fine  adjustment  is  found  at  the  top  of  tho 
pillar. 

Carefully  turn  the  fine  adjustment  back  and  fortli.  (Xo  more  than  half  a  turn 
in  either  direction!)     Why  is  this  adjustment  called  "fine"? 

Problem.  19:  To  deterinine  tlie  unit  of  striictnrr  in  jtlant^i 
and  animals. 

Materials.  —  Onion  skin,  scrapinjz;s  from  mouth,  compound 
microscope,  slides,  methyl  blue. 

Method.  —  Scrape  some  cells  from  the  inside  linini::  of  tiie  clicok 
with  a  sterilized  knife.  Mount  in  water.  Stain  with  methyl  Mue. 
Onion  skin  may  be  used  and  stained  with  methyl  blue  or  iodine. 

Note.  —  a  cell  is  a  .small  living  structure  made  up  of  living  matter  (proto}>lasm) 
containing  a  portion  which  in  part  readily  absorbs  stain.     This  structure  ia  called 
the  nucleus.     A  cell  is  usually  bounded  by  a  cell  wall  or  ccJl  membrane. 
HUNTER   LAB.    PROS. — 4 


50 


FUNCTIONS   OF   LIVING   THINGS 


Diagram  Showing  Cells. 
N,  nucleus  ;  P,  protoplasm  ;  W,  walls. 


Observations.  —  What  is  the 
shape  of  a  single  cell?  Are 
all  cells  examined  the  same 
size?  Shape?  Can  you  lo- 
cate the  nucleus  (a  deeply 
stained  body) ,  cytoplasm  (pro- 
toplasm outside  the  nucleus), 
and  cell  wall?  Any  other 
structures  ? 

Are  the  cells  separate  or 
united  with  one  another? 


Note.  —  Cells  of  the  same  sort  joined  together  in  a  plant  or  an  animal  form 
tissues.  Tissues  are  grouped  in  both  plants  and  animals  to  form  organs,  struc- 
tures which  have  some  certain  work  to  do,  as  a  leaf,  a  root,  a  hand,  an  eye,  etc. 

Conclusion.  —  1.  In  the  onion  do  the  cells  form  tissues?  Give 
reason  for  your  answer. 

2.  What  are  tissues  ?     Of  what  are  tissues  composed  ? 

3.  What  are  organs?     Give  examples  from  your  own  body. 

4.  Define  a  cell  from  what  you  have  seen  under  the  microscope. 

5.  (Optional.)  Draw  a  few  of  the  cells  stained  with  methyl 
blue  or  iodine,  showing  cell  walls,  nuclei,  and  protoplasm. 

Pi^obletn  20 :  To  determiiie  some  of  the  properties  of  proto- 
plasm. 

Materials.  —  Stamen  hairs  of  spiderwort  {Tradescantia) ,  leaves 
of  Elodea,  or  the  root  hairs  of  radish  or  grain  seedlings  are  useful. 
As  Elodea  is  easily  grown  in  aquaria,  it  is  recommended  for  this 
exercise. 

Observations.  —  Examine  a  bit  of  mounted  leaf  of  Elodea. 
What  is  its  general  appearance  under  the  low  power?  Can  you 
locate  individual  cells  in  the  mass  ?  Note  the  green  bodies  in  the 
cells  {chlorophyll  bodies) .  Can  you  find  the  cell  walls  ?  The  liv- 
ing matter  (protoplasm)  ? 

Look  closely  along  the  edge  of  the  cells  for  any  movement  of 
living  matter  within  the  cell.  Does  the  protoplasm  move  in  any 
particular  direction? 


PUUBLE.M   22  51 

Heat  the  slide  very  slightly.  Wliat  is  llic  rcsuh  ?  (ool  tlic 
slide  and  note  the  effect  on  cell  movenieiil. 

Conclusion.  —  1.  In  what  part  of  planls  may  j)n)t()pla>ni  Ik; 
found  ? 

2.  Write  a  paragraph,  descri})in<2;  tlic  :ii)|)('aiaii('c.  niovcnicnt, 
and  composition  of  protoplasm  in  Elodcu.  \\  hat  arc  its  rcdduniH 
(look  up  this  word  in  the  dictionary)  to  heat  and  cold? 

Problem  21 :  To  study  structure  and  groivth  oj' iJoUcn. 

Materials.  —  Pollen  of  snapdragon,  sweet  i)ea,  nit-^turtium,  or 
tulip;  sugar  solution  (3  per  cent,  10  per  cent,  and  1')  per  cent), 
bell  jar,  sponge,  a  compound  microscope,  hand  lens. 

Method. — ^Dust  some  pollen  of  snaptlragon  on  a  glass  sHde. 
Examine  it  with  a  hand  lens.  Make  a  10  per  cent  sohition  of  cano 
sugar  and  dust  some  ripe  pollen  in  a  drop  of  the  solution  placed 
on  a  glass  slide.  Place  this  slide  under  a  small  Itcll  jai-  with  a 
moist  sponge  and  examine  after  24  hours  with  the  low  j)owcr  of 
the  compound  microscope.  Try  sweet  pea  or  nasturtium  pollen 
in  a  15  per  cent  sugar  solution,  or  tulip  with  a  '-^  i)er  cent  su^ar 
solution. 

Observations.  —  Look  for  a  tubelike  structure,  the  p<tUvn  tiibe, 
growing  out  of  the  pollen  grains.     Describe  and  sketch  one. 

Conclusion.  —  1.  What  made  the  pollen  tulx^  grow? 

2.  Under  what  other  condition  have  you  heard  of  the  growth  of 
pollen  ? 

Problem  22:  To  study  the  reason  for  the  growth  of  jk,!! en- 
grains in  fioiuers. 

Method  and  Observations.  — Study  the  following  diagram,  the 
figures,  pages  53  and  54,  in  your  Civic  HioUnjij,  and  charts 
for  further  explanation.  Within  the  pollen  tube  is  a  ceil  known 
as  the  sperm  cell.  Note  that  the  cell  in  the  end  (.f  the  jxjllen 
tube  is  about  to  unite  with  the  egg.  Observe  the  i)athway  taken 
by  the  pollen  tube.  How  does  the  sperm  cell  from  the  i)ollen 
grain  get  into  the  ovary?  Study  th(»  longitudinal  s.'ction  of  the 
ovary.  Note  a  number  of  ovoid  bodies  (ondcs)  in  the  ovary. 
How  could  a  pollen  tube  reach  an  ovule  ? 


52 


FUNCTIONS  OF   LIVING   THINGS 


NOTE.  —  If  a  sperm  cell  reaches  a  large  cell  (called  an 
egg)  located  in  the  oviile,  the  sperm  and  the  egg  unite  to 
form  a  single  cell.  The  egg  cell  is  then  said  to  be  fertilized. 
This  process  is  known  as  fertilization.  After  fertilization 
the  egg  will  grow  into  a  tiny  structure  known  as  an  embryo. 
The  ovxile  then  is  known  as  a  seed.  The  embryo  within  the 
seed  will,  under  favorable  conditions,  develop  into  a  young 
plant. 

Conclusion.  —  1.  What  is  fertilization  and 
how  does  it  take  place  ? 

2.  What  results  from  fertilization  of  the  egg 
of  a  flower? 

3.  Why  are  the  stamens  and  pistils  called 
essential  organs? 

4.  Why  is  the  process  of  fertilization  nec- 
essary ? 


1,  pollen  grain  ;  2,  at 
time  it  falls  upon 
stigma ;  3,  starting 
to  grow ;  4,  with  a 
pollen  tube;  s, 
sperm  cell  nucleus. 


Problem  23 

fojnned. 


To  discover  how  fruits  are 


a.  The  Bean 


Materials.  —  Pea  or  bean  flowers,  bean  pods. 
Diagram,  page  55,  Civic  Biology. 
Method    and    Observations.  —  Examine    an    unopened    pod. 
Compare  it  with  the  pistil  of  an  old  flower.     Find  the  ovary  or 
seed  case,  the  style,  and  the  stigma.     Open  the  pod.    Notice  the 
little  seeds.     How  are  they  attached  to  the  pod?     Why  are  not  all 
the  seeds  the  same  size?     (Look  up  the  diagram  on  fertilization.) 
Conclusion.  —  1.  What  part  of  the  flower  forms  the  bean  fruit? 
2.  What  is  one  use  of  a  fruit  to  the  plant? 
Drawing.  —  Draw  an  opened  pod  showing  the  seeds.     Label 
all  the  parts. 

b.   The  Apple 

Materials.  —  Apple  blossoms  in  various  stages,  or  chart. 
Apples.     Diagram,  page  56,  Civic  Biology. 

Observations.  —  In  an  apple  blossom  how  are  the  sepals  placed 
with  reference  to  the  ovary,  above  or  below  it  ?  Note  the  position 
and  appearance  of  the  receptacle,  or  base,  of  the  flower. 

Observe  several  young  apples  in  different  stages  of  develop- 


PROBLEM   24 


53 


ment.  What  parts  of  the  flower  appear  to  gJ'ow  into  the  fruit? 
Cut  cross  and  longituchnal  sections  of  an  apple.  Find  seed  cases 
of  the  ovary.     How  many  are  there?     What  do  you  find  in  them? 

Conclusion.  —  1.  From  what  does  the  fleshy  part  of  the  apple 
develop?     The  part  that  holds  the  seeds? 

2.  Give  reasons  for  your  answer  in  a  well  written  paragraph. 

Problem  24 :  How  and  why  fruits  and  seeds  are  scattered. 

Materials.  —  Fruits  of  burdock,  jinison  weed,  clotbur,  thistle, 
beg;gar's  tick,  maple,  linden,  dandelion,  crane's-bill,  raspberry, 
acorn,  peac/h,  chestnut,  pines,  and  witch-hazel  in  boxes  or  glass 
bottles. 

Method.  —  Collect  as  many  as  possible  of  the  above-mentioned 
fruits  and  seeds'  yourself,  taking  notes  on  where  they  were  found. 
Any  overgrown  city  lot  will  yield  some  of  the  above,  a  trip  to  a  park 
or  to  the  country  in  the  fall  will  give  you  many  more.  The  rest 
may  be  obtained  from  your  instructor.  After  bringing  your  mate- 
rial to  class,  place  it  in  boxes  provided  for  that  purpose. 

Observations.  —  Classify  your  fruits  and  seeds  in  the  following 
table,  giving  means  of  scattering : 


Wiivd 
Carried 

Burrs  awdi 
Stickers 

Explosive 

Birds 

K«»^ 

\V^€xteT- 

o  1 1\  e  1- 

Conclusion.  —  1.  Write  a  paragraph  telling  the  devices  you  have 
found  in  the  seed  or  fruit  to  help  it  be  scattered.  Also  tell  all 
the  ways  in  which  seeds  or  fruits  may  be  scattered. 

2.  Give  as  good  a  reason  as  you  are  able,  why  it  is  desirable  for 
plants  to  scatter  their  seeds  and  fruits  at  some  distance  from  the 
parent  plants. 

Problem  Questions 

1.  What  are  the  needs  of  living  things? 

2.  What  are  the  functions  of  living  things? 


54  FUNCTIONS   OF  LIVING   THINGS 

3.  Why  is  reproduction  such  an  important  function  ? 

4.  What  is  the  difference  between  polhnation  and  f ertihzation  ? 

5.  What  are  the  parts  of  a  cell?     The  functions  of  a  cell? 

6.  What  are  the  characteristics  of  living  matter? 

7.  What  are  the  properties  of  living  matter? 

8.  What  part  of  a  flower  becomes  the  fruit? 

9.  Why  is  it  important  for  plants  to  scatter  their  fruits? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  IV.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chap.  III.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  III.     American  Book  Company. 

Andrews,  Botany  All  the  Year  Round,  pp.  222-236.     American  Book  Company. 

Atkinson,  First  Studies  of  Plant  Life,  Chaps.  XXV-XXVI.     Ginn  and  Company. 

Bailey,  Lessons  with  Plants,  Part  III,  pp.  131-150.     The  Macmillan  Company. 

Bailey,  Plant  Breeding.     The  Macmillan  Company. 

Campbell,  Lectures  on  the  Evolution  of  Plants.     The  Macmillan  Company. 

Coulter,  Plant  Studies,  Chap.  VII.     D.  Appleton  and  Company. 

Coulter,  Barnes,  and  Cowles,  A   Textbook  of  Botany,  Part  II.     American  Book 

Company. 
Curtis,  Nature  and  Development  of  Plants.     Henry  Holt  and  Company. 
Dana,  Plants  and  Their  Children,  pp.  187-255.     American  Book  Company. 
Darwin,  Different  Forms  of  Flowers  on  Plants  of  the  Same  Species.     D.  Appleton 

and  Company. 
Darwin,  Fertilization  in  the  Vegetable  Kingdom,  Chaps.  I  and  II.     D.  Appleton 

and  Company. 
Darwin,  Orchids  Fertilized  by  Insects.     D.  Appleton  and  Company. 
Ganong,  The  Living  Plant,  Chap.  XI.     Henry  Holt  and  Company. 
Gray,  Structural  Botany.    .American  Book  Company. 

Jost,  Lectures  on  Plant  Physiology.     Tr.  by  R.  J.  H.  Gibson.     Frowde,  London. 
Lubbock,  Flowers,  Fruit,  and  Leaves,  Part  I.     The  Macmillan  Company. 
Lul)bock,  British  Wild  Flowers.     The  Macmillan  Company. 
Miiller,  The  Fertilization  of  Flowers.     The  Macmillan  Company. 
Newell,  A  Reader  in  Botany,  pp.  1-96.     Ginn  and  Company. 
Sharpe,  A  Laboratory  Manual  in  Biology.     American  Book  Company. 


V.   PLANT  GROWTH  AND   NUTRITION.    CAUSES  OF 

GROWTH 

Problein.  —  What  causes  a  young  ])Iaiit  to  grow? 
(a)   The  relation  of  the  young  ])Jant  to  its  food  suf)j)hj. 
ib)   The  outside  conditions  necessary  for  germination. 
(c)    What  the  young  ])lant  does  with  its  food  supply, 
id)  How  a  plant  or  animal  is  able  to  use  its  food  su])])ly. 
(e)  How  a  plajtt  or  animal  prepaj^es  food  to  use  in  various 
parts  of  the  body. 

Laboratory  Suggestions 

Laboratory  exercise.  —  Exainination  of  bean  in  pod.  Examination 
and  identification  of  parts  of  bean  seed. 

Laboratory  demonstration.  —  Tests  for  the  nutrients  :  starch,  fats  or 
oils,  protein. 

Laboratory  demonstration.  —  Proof  that  such  foods  exist  in  bean. 

Home  work.  —  Test  of  various  common  foods  for  nutrients.  Tabulate 
results. 

Extra  home  work  by  selected  pupils.  —  Factors  necessary  for  germination 
of  bean.     Demonstration  of  experiments  to  class. 

Demonstration.  —  Oxidation  of  candle  in  closed  jar.  Test  with  lime- 
water  for  products  of  oxidation. 

Demonstration.  —  Proof  that  materials  are  oxidized  within  the  human 
body. 

Demonstration.  —  Oxidation  takes  place  in  growing  seeds.  Test  for 
oxidation  products.     Oxygen  necessary  for  germination. 

Laboratory  exercise.  —  Examination  of  corn  on  cob,  the  corn  grain, 
longitudinal  sections  of  corn  grain  stained  with  iodine  to  show  that  em- 
bryo is  distinct  from  food  supply. 

Demonstration,.  —  Test  for  grape  sugar. 

Demonstration.  —  Grape  sugar  present  in  growing  corn  grain. 

Demonstration.  —  The  action  of  diastase  on  starch.  Conditions  neces- 
sary for  action  of  diastase. 

To  THE  Teacher.  —  One  of  the  most  essential  reasons  for  placinK  biology  early 
in  the  school  curriculum  is  due  to  the  fact  that  as  an  experimental  science  it  makes 
for  straight  thinking.  If  any  one  chapter  in  this  book  lends  itself  to  logical  devel- 
opment, it  is  the  chapter  that  follows.     All  laboratory  work  here  outlined  builds, 

bo 


56  PLANT   GROWTH   AND   NUTRITION 

step  by  step,  the  general  concepts  of  the  necessity  for  food,  for  digestion  of  food, 
and  for  the  oxidation  of  food  for  the  release  of  energy.  The  food  tests  are  inci- 
dentally shown,  as  they  should  be,  in  connection  with  the  main  problem  of  food  in 
its  relation  to  the  young  plant.  All  tests  as  tests  are  subordinated  to  the  main 
problems  as  outlined  above.  Thus  the  pupil  gets  his  incidental  information  about 
certain  factors  of  the  environment  of  the  young  plant  by  means  of  association. 
Throughout  this  entire  chapter  a  conscious  effort  should  be  made  by  the  teacher 
to  correlate  the  processes  which  go  on  in  the  young  developing  plant  with  the  same 
fundamental  processes  wdiich  go  on  in  the  human  body.  Thus  experimental  proof 
lays  a  foundation  for  the  work  in  human  physiology  later. 


Problem  25 :  To  find  the  relation  of  the  embryo  to  the  food 
supply. 

Materials.  —  Dry  pods  containing  beans,  soaked  beans. 

Method  and  Observations.  —  Open  the  pods  and  pull  a  bean 
from  its  attachment.  Note  the  scar  where  the  bean  was  attached. 
This  is  called  the  kilum. 

Look  for  a  tiny  hole,  the  micropyle,  at  one  end  of  the  hilmn. 
It  was  through  this  hole  that  the  sperm  cell  reached  the  egg  cell 
{micropyle  means  ''little  gate"). 

Peel  off  the  outer  coat  (testa)  of  a  soaked  bean.  What  use 
might  it  have  ? 

Note  that  the  bean  separates  into  two  parts,  called  the  cotyledons. 
Take  off  one  cotyledon  very  carefully,  and  find  two  tiny  folded 
leaves,  the  plumules,  and  a  rodlike  part,  the  hypocotyl.  How  does 
the  hypocotyl  point  with  reference  to  the  hilum  edge  of  the  bean? 

All  the  parts  within  the  seed  coat  are  collectively  known  as 
the  embryo. 

Conclusion.  —  1.  How  is  the  embryo  protected? 

2.  Can  you  find  a  use  to  the  young  plant  of  the  hypocotyl? 
The  plumule?     The  cotyledon? 

3.  Compare  the  bean  seed  with  some  growing  beans  (seedlings) 
a  week  or  two  old.     How  can  you  answer  the  questions  above? 

4.  Notice  in  the  older  beans  the  cotyledons  seem  to  be  smaller 
than  in  the  beans  that  have  not  sprouted.  To  account  for  this 
let  us  learn  how  to  test  for  certain  food  substances  or  nutrients, 
then  after  making  these  tests,  apply  the  same  tests  to  the  bean 
cotyledon  and  draw  some  valid  conclusions  as  to  the  use  of  the 
cotyledon. 


PROBLEM   27  57 

Tests   for   Organic   Nutrients 

Problem  26 :  To  test  for  starch. 

Materials.  —  Cornstarch,  iodine  solution/  and  test  tube. 

Method  and  Observations. — Add  a  small  bit  of  starch  to  a 
test  tube  containing  a  little  cold  water.  Add  a  few  drops  of  iodine 
solution.  Note  the  result.  Make  a  little  starch  paste  by  heating 
with  water ;  cool,  add  iodine  as  before.  Do  you  get  the  same 
result  ? 

Note.  —  The  presence  of  starch  and  no  other  known  substance  is  shown  by  a  change 
to  a  deep  blue  color  on  addition  of  iodine. 

Now  mash  up  a  little  of  the  bean  cotyledon  and  add  iodine. 
Is  there  any  starch  in  the  bean?  Work  out  in  experiment 
form. 

Conclusion.  —  How  would  you  detect  the  presence  of  starch  in 
a  substance? 

Problein  27 :  To  test  for  grape  sugar, 

a.  Test  with  Fehling's  Solution 

Materials.  —  Glucose,  Fehling's  solution,-  test  tubes,  Bunsen 
burner. 

Method.  —  Place  in  a  test  tube  a  little  glucose  and  water, 
add  an  equal  amount  of  Fehling's  solution.  Heat  to  the  boil- 
ing point. 

Observations. — What  color  changes  take  place? 

Note.  —  if  the  color  of  the  mixture  becomes  brick  red  upon  heating,  then  grape 
sugar  is  present. 

Conclusion.  —  Is  grape  sugar  present  in  the  substance  tested? 

^  Iodine  solution  may  be  made  by  adding  a  few  crystals  of  iodine  to  enough  95 
per  cent  alcohol  to  dissolve  it  well.  Or  to  1  gram  of  iodine  crystals,  add  f  gram  of 
potassium  iodide,  and  dilute  to  a  dark  brown  color  in  35  per  cent  alcohol. 

2  Fehling's  solution  may  be  made  as  follow.s  :  Add  35  g.  of  copper  .sulphate  to 
500  c.c.  of  water.     Solution  No.  1. 

To  160  g.  caustic  soda  (sodium  hydroxide),  and  173  g.  Rochelle  salt,  add  500  v. v. 
of  water.     Solution  No.  2. 

For  use  mix  equal  parts  of  solutions  1  and  2.  This  may  also  be  obtained  of 
druggists,  in  tablet  shape. 


58  PLANT   GROWTH   AND   NUTRITION 

b.   Test  with  Benedict's  Solution 

Materials.  —  The  same  as  above,  but  substitute  for  Fehling's 
solution  Benedict's  second  solution.^ 

Method.  —  Place  the  material  to  be  tested  in  a  test  tube  with 
an  equal  amount  of  Benedict's  solution.  Heat  to  boiling.  Con- 
tinue boiling  for  two  minutes. 

Observations.  —  Are  there  any  changes  in  color? 

Note.  —  if  grape  sugar  is  present,  a  precipitate  will  be  formed  having  a  red,  yel- 
low, or  green  color,  depending  upon  the  amount  of  sugar  present. 

Conclusion.  —  1.  Is  grape  sugar  present  in  the  material  tested? 

2.  Test  apples,  grapes,  bananas,  pears,  or  any  other  fruit  to  see 
whether  grape  sugar  is  present. 

3.  Make  a  table  showing  the  amount  of  grape  sugar  present  in 
various  foods. 

Prohle^n  28 :  To  test  for  fats  and  oils. 

Materials.  —  Nuts  or  animal  fat,  white  paper. 

Method.  —  Rub  the  nut  or  material  to  be  tested  on  a  piece  of 
paper,  and  hold  to  the  light,  or  put  material  to  be  tested  on  a  piece 
of  white  paper  in  an  oven  for  a  few  minutes. 

Observations.  —  What  happens  to  the  paper? 

Conclusion.  —  How  would  you  know  the  presence  of  oil  in  a 
substance? 

Note.  —  Ether  and  benzine  extract  oils  from  substances,  and  on  evaporation 
leave  the  oil  on  the  container. 

Test  beans  in  this  manner  and  write  out  in  problem  form  for  extra  credit. 

Problem  29 :  To  test  for  proteins  or  nitrogenous  foods. 
Materials.  —  Raw  and  hard-boiled  white  of  egg,   hair,   nitric 
acid,  ammonia,  test  tubes. 

1  Benedict's  second  solution.  —  Copper  sulphate 17.3  g. 

Sodium  citrate 173.0  g. 

Sodium  carbonate  (anhydrous)    .     .     .    100.0  g. 
Make  up  to  1  liter  with  distilled  water. 

With  the  aid  of  heat  dissolve  the  sodium  salts  in  about  600  c.c.  of  water.     Pour 

through  filter  paper  into  a  glass  graduate  and  make  up  to  850  c.c.  with  distilled  water. 

Dissolve  the  copper  sulphate  in  about  100  c.c.  of  Avater,  and  make  up  to  150  c.c. 

with  distilled  water.     Pour  the  carbonate  citrate  solution  into  a  large  beaker  and 

add  the  copper  sulphate  solution  slowly  with  constant  stirring. 

After  Hawke's  Biochemistry. 


PROBLEM  :^0  59 

Method. — ^  Place  material  to  bo  tested  in  a  test  tulx',  with  a 
little  strong  nitric  acid,  and  heat  gently.  Note  any  color  that 
appears.  Rinse  with  water  to  wash  off  acid.  Add  a  little  am- 
monia and  note  any  change  in  color. 

Observations.  —  What  change  in  color  takes  place  when  the 
material  is  heated  with  nitric  acid? 

NOTE.  —  If  a  lemon-yellow  color  appears  after  the  addition  of  nitrif  acid  fol- 
lowed by  a  deep  orange  color  on  addition  of  ammonia,  there  is  protein  present. 

Home  Experiments.  Method  1.  —  Put  some  white  of  egg  in  a 
saucepan  and  heat  it. 

Observations.  —  What  happens  as  the  white  of  egg  is  heated  ? 

Note.  —  Any  substance  thickening  and  becoming  white  in  color  is  said  to 
coagulate,  and  this  indicates  the  presence  of  an  albumen  (a  protein). 

Method  2.  —  Burn  a  hair,  a  feather,  or  a  piece  of  meat. 

Observations.  —  Note  the  peculiar  odor  of  burning  hair  or 
feather.     This  shows  the  presence  of  a  protein. 

Conclusion.  —  1.  What  are  three  ways  of  knowing  the  presence 
of  proteins  in  a  given  substance? 

2.  By  means  of  the  nitric  acid  and  ammonia  test,  find  out 
whether  there  is  protein  present  in  the  cotyledons  of  beans. 
Write  up  in  experimental  form. 

Tests   for   Inorganic   Nutrients 

Problefn  30:    To  test  for  the  presence  of  mineral  viatter. 

(Optional.) 

Materials.  —  Meat,  tin  plate,  and  flame. 

Method.  —  Heat  a  piece  of  meat  in  a  tin  plate  over  a  venj  hot 
fire. 

Observations.  —  Does  all  the  meat  disappear?  Describe  what 
is  left. 

NOTE.  —  The  remainder  is  a  tasteless  or  slightly  salty  mass  of  mineral  matter. 

Conclusion.  —  How  can  you  determine  whether  a  substance 
contains  mineral  matter? 

Home  Work.  —  Test  beans  to  see  whether  there  is  any  mineral 
matter  present,  remembering  that  when  heated  to  a  sufficient  tern- 


60 


PLANT   GROWTH   AND   NUTRITION 


perature,  all  organic  material  disappears ;  the  remainder  is  ash  or 
mineral  matter. 


Problem  31 :  To  test  for  the  presence  of  water. 

Materials.  —  Meat,  oven,  balance. 

Method.  —  AVeigh  a  piece  of  meat.  Place  it  in  a  warm  oven 
until  it  is  thoroughly  dry,  then  reweigh  it. 

Observations.  —  What  percentage  of  its  original  weight  does 
the  meat  lose? 

Conclusion.  —  1 .  What  is  the  cause  of  most  of  the  loss  in  weight  ? 

2.  As  a  result  of  your  experiments,  write  a  short  statement  as 
to  what  organic  and  inorganic  nutrients  are  present  in  the  bean. 

3.  What  happens  to  the  nutrients  when  the  young  plant  grows? 
Give  reasons  for  your  answers. 

Problem  32:  To 
test  various  food  sub- 
stances for  the  or- 
ganic nutrients. 
(Home  Work.) 

Materials.  —  Pupils 
may  be  supplied  with 
testing  chemicals  to 
take  home  or  this  exer- 
cise may  well  be  a  lab- 
oratory exercise. 

Method  and  Obser- 
vations. —  Test  with 
chemicals,  as  above, 
as  many  different  foods 
as  possible,  said  foods 
to  include  meats,  ce- 
reals, nuts,  vegetables, 
fruits.  Make  a  table 
like  the  accompanying. 
After  testing  a  food  for 
a  given  nutrient  place 
one  of  the  three  fol- 


Tested 

T '     ■ 

1 

5/) 

O 

e 

•rl 
0) 

-M 

e 

Potciio 

Bread 

BearvS 

^00" 

Peanut 

Qpple 

Butfer 

'test  Usee 

Use  o/" 
nutrient 

PROBLEM   33 


Gl 


lowing  words  in  the  proper  colunni  on  a  line  witli  the  food 
tested :  none,  little,  much.  Several  pupils  may  work  togethcM- 
and  give  their  results  to  the  class  so  as  to  make  the  record  cover 
as  many  foods  as  possible. 

Conclusion.  —  1.  Name  five  common  foods  rich  in  protein;  in 
starch ;  in  grape  sugar ;  in  oil ;  in  water. 

2.  Verify  your  results  by  comparing  with  food  charts  on  pages 
278-279  of  your  Civic  Biology. 

A  Study  of  the  Conditions  needed  to  awaken  the  Embryo 

IN  THE  Seed 

Problem  33 :  To  show  how  much  water  is  needed  to  make  a 
seed  germinate.     (Home  Experiment.) 

Materials.  —  Soaked  peas,  sawdust,  cups. 

Method.  —  Pupils  performing  this  or  any  other  experiments 
must  remember  that  the  success  of  an  experiment  depends  upon 
the  accuracy  with  which  it  is  performed  and  the  exclusion  of  all 
factors  from  the  experiment  except  the  one  which  you  are  trj'ing  to 
prove.  For  example,  in  the  following  experiment  on  the  effect 
of  different  amounts  of  moisture,  all  the  other  factors  —  tempei-a- 
ture,  light,  food,  etc.  —  must  be  the  same  in  each  of  the  three 
cups ;  the  only  variable  factor  being  moisture.  Place  an  equal 
amount  of  moist  sawdust  in  the  bottom  of  each  of  three  cups. 
Put  ten  soaked  peas  in  each.  Keep  the  seeds  in  one  cup  very  wet, 
those  in  the  second  slightly  moistened,  and  those  in  the  third  dry. 
Keep  the  cups  covered  in  a  moderately  warm  place.  Examine 
them  daily  for  seven  days. 

Observations.  —  Tabulate  results  as  follows  : 

ISTx^  reviser'       oj"    T^e  ct  s     Spr^ovttecl 


Dc^ 

Dr^ 

Moi^t 

^A/^et 

Fii-st          D«x 

Second.      Dcry 

etc.,tov3eveT\  Y^ayS 

62 


PLANT   GROWTH   AND   NUTRITION 


Conclusion.  —  What  amount  of  water  seems  best  for  germina- 
tion?    Give  your  reasons. 

Problem  :M:  To  determine  tJie  temperature  best  fitted  to 
cause  peas  to  germinate.    (Home  Experiment.) 

Materials.  —  Soaked  peas,  sawdust,  boxes. 

Method.  — -  Plant  twenty  soaked  peas  in  each  of  three  boxes 
filled  with  moist  sawdust.  Put  one  box  where  the  temperature 
is  about  90°  F.,  another  where  the  temperature  is  about  70°  F., 
and  the  third  where  the  temperature  is  about  40°  F.  Give  all 
the  same  conditions  of  air,  light,  and  moisture.  Observe  them 
for  ten  days. 

Observations.  —  Tabulate  the  daily  observations  as  follows  : 


Xe  jn  p  efnt  vire 

r* 

.^s. 

^rf^ 

1st 

2.Txd 

3cl 

4tK 

5tK 

6tK 

7tK 

8±K 

StK 

lOtK 

90<iegrees 

70  deg-j[»ee^ 

^Odeg-i-ees 

Conclusion.  —  What  temperature  seems  best  for  germinating 
seeds?     Reasons. 

Problem  35 :  To  show  that  seeds  need  some  part  of  the  air  in 
order  to  grow. 

Materials.  —  Wide-mouth  bottles,  sand,  soaked  peas,  corks, 
paraffin. 

Method  and  Observations.  —  Fill  five  flasks  with  varying 
amounts  of  wet  sand  so  that  one  bottle  contains  very  little  air  and 
others  are  one  quarter,  half,  and  three  quarters  full  of  air.  Put 
an  equal  number  of  soaked  peas  into  each  bottle.  Cork,  and 
paraffin  each  cork  so  as  to  allow  no  air  to  enter.  Place  where  all 
will  have  the  same  conditions  of  heat  and  light.  Note  daily 
growth  on  a  table  like  the  following. 

Conclusion.  —  In  which  bottles  do  the  peas  grow  best?     Why? 


PROBLEM   37 


63 


Numbar 
o|  Poas 

Sprouted 

• 

BTB 

A 

n 

A 

A 

ist  Day 

2nd    .. 

3d     .. 

4th   .. 

5th   .. 

6th    .. 

7th    .. 

8th  .. 

9th   .. 

10th    .. 

Problem  3G:  To  show  that  food  is  needed  by  the  emhryu  in 
order  to  grow. 

Materials.  —  Growing  pea  and  bean  seedlings. 

Method.  —  We  have  ah-eady  found  that  beans  contain  a  supply 
of  food  for  the  young  plant.  Test  peas  to  see  if  food  is  also  pres- 
ent in  the  cotyledons.  After  the  peas  and  beans  have  begun  to 
germinate  remove  the  cotyledons  and  place  them  under  favor- 
able conditions  for  continued  growth.  What  happens?  Allow 
bean  seedlings  to  grow  to  a  height  of  an  inch,  then  remove  both 
cotyledons  from  some,  one  cotyledon  from  others,  and  leave  others 
with  both  cotyledons  for  controls.     Which  grow  most  rapidly? 

Conclusion.  —  What  do  you  conclude  from  these  results? 


rrohleni  37.  Is  any  part  of  the  air  necessary  for  combustion  ? 

(Demonstration. ) 

NOTE. — We  have  seen  that  seeds  use  up  food  in  order  to  urow  and  that  .-^ocds 
grow  only  in  the  presence  of  air.  We  must  now  study  the  air  in  order  Xm  fintl  wliat 
there  is  in  it  that  enables  seeds  to  use  food  and  release  the  energy'  necessary  for 
growth. 


64  PLANT   GROWTH   AND   NUTRITION 

Materials.  —  Bit  of  phosphorus,  dish,  float,  bell  jar. 

Method.  —  Place  a  bit  of  phosphorus  on  cork  and  float  it  in  a 
pan  of  water.  Ignite  the  phosphorus  and  quickl}^  invert  a  bell 
jar  over  it. 

Observations.  —  What  happens  to  the  phosphorus?  What 
happens  to  the  water  in  the  pan  ? 

NOTE.  —  Air  is  composed  principally  of  two  elements,  nitrogen  (about  79  per 
cent)  and  oxygen  (about  20  per  cent).  When  the  phosphorus  burns,  it  unites  with 
one  of  the  elements  and  forms  a  substance  which  dissolves  in  water.  (See  p.  20, 
Civic  Biology.) 

Conclusion. — Judged  by  the  amount  of  air  which  is  dis- 
placed by  water,  which  of  the  two  gases  of  the  air  was  used  up  ? 

Prohlein38:  To  test  for  oxygen-     (Demonstration.) 

NOTE.  — Certain  tests  may  be  made  by  which  the  presence  of  some  of  the  gases 
which  compose  the  air  may  be  isolated  and  studied.  Pure  oxygen,  a  colorless  and 
odorless  gas,  is  known  by  its  ability  to  support  combustion. 

Materials.  —  Oxone,  potassium  chlorate,  black  oxide  of  man- 
ganese, Bunsen  flame,  test  tube  with  cork  and  delivery  tube, 
wide-mouth  bottle,  large  dish. 

Method.  —  Heat  a  little  potassium  chlorate  in  a  test  tube  with 
about  the  same  amount  of  black  oxide  of  manganese.  Chemical 
action  takes  place  which  results  in  the  evolution  of  oxygen.  This 
may  be  collected  by  a  delivery  tube  or  used  in  the  test  tube. 
Instead  of  this  method,  a  patented  substance  known  as  oxone 
may  be  used.  A  small  piece  of  oxone  placed  in  water  will  liberate 
enough  oxygen  for  several  tests.  The  gas  may  be  collected  with 
the  aid  of  a  delivery  tube  by  displacing  water  from  test  tubes  or 
bottles. 

Observations.  —  In  a  test  tube  containing  oxygen  plunge  the 
glowing  end  of  a  match.  What  happens  to  the  glowing  match? 
What  difference  is  there  between  the  burning  of  the  match  in 
air  and  in  oxygen? 

Place  a  piece  of  red-hot  iron  wire  in  oxygen  ;  a  piece  of  heated 
magnesium  wire.     What  happens  in  each  case  ? 

Note.  —  When  oxygen  combines  -w-ith  any  substance,  the  process  is  called 
oxidation.  The  substance  with  which  the  oxygen  unites  is  said  to  be  oxidized,  and 
heat  is  released  as  a  result  of  the  process. 


PROBLEM  40  G5 

When  an  iron  nail  is  placed  in  a  damp  plar-o,  it  rusts.  This  is  also  an  oxidation, 
the  iron  of  the  nail  uniting  with  the  oxygen  of  the  air. 

Conclusion.  —  1*.  Explain  exactly  what  happens  when  a  jj;low- 
ing  match  is  placed  in  pure  oxygen. 

2.  Is  it  correct  to  say  that  oxygen  burns  up? 

3.  What  !§  always  released  as  a  result  of  oxidation? 

4.  Explain  the  difference  between  rapid  oxidation  (combustion) 
and  slow  oxidation. 

Problem  39 :  To  test  for  carbon. 

Materials.  —  Meat,  bread,  starch,  etc.,  glass  plate,  candle.  Fig- 
ure page  65,  Civic  Biology. 

Note.  —  All  organic  substances  contain  the  chemical  element  carbon.  This 
may  be  proved  by  burning  a  substance.  If  it  becomes  charred  or  blackened,  it 
contains  carbon. 

Method  and  Observations.  —  Test  meat,  bread,  dried  peas,  and 
starch  for  carbon. 

Hold  a  clean  piece  of  glass  over  the  flame  of  a  candle.  What 
forms  on  the  glass?     Where  does  it  come  from? 

Conclusion.  —  Make  a  table  showing  substances  tested,  noting 
whether  or  not  they  contain  carbon. 

Problem  40 :  To  test  for  carbon  dioxide. 

Note.  —  We  have  seen  that  substances  that  burn  unite  with  the  oxj'gen  of  the 
air  when  they  are  oxidized.  Let  us  next  see  what  happens  to  the  air  when  carbon 
unites  with  oxygen. 

Materials.  —  Candle,  limewater,^  wide-mouth  bottle. 

Method.  —  Burn  a  candle  (which  has  been  proved  to  contain 
carbon)  in  a  wide-mouth  bottle,  then  add  a  little  limewater  and 
shake  the  bottle. 

Observations.  —  What  change  takes  place  in  the  limewater? 

Note.  —  a  gas  called  carbcn  dioxide  causes  limewater  to  become  milky. 

Conclusion.  —  1.  How  is  carbon  dioxide  formed? 

2.  What  is  the  test  for  the  presence  of  carbon  dioxide? 

3.  Explain  this  formula,   C  +  2  O  =  CO,. 

^  Limewater  is  made  by  adding  a  piece  of  quicklime  the  size  of  your  fist  to  about 
2  quarts  of  water.     Filter  before  using. 
HUNTER   LAB.    PROB. — 5 


66 


PLANT   GROWTH   AND   NUTRITION 


Problem  41 :  To  prove  that  organic  suhstances  are  oxidized 
within  the  human  body. 

Materials.  —  Wide-mouth  bottle,  glass  tube,  limewater. 
Method  and  Observations.  —  Force  the  breath  through  a  tube 
.  into  limewater.     What  happens? 

Conclusion.  —  1.  What  is  one  substance  that  comes  from  the 
lungs  ? 

2.  How  and  where  must  this  substance  have  been  formed? 

3.  If  oxidation  takes  place  in  the  human  body,  and  heat  or 
energy  is  released  as  a  result  of  this  oxidation,  then  something 
must  be  oxidized  within  the  human  body  when  it  does  work.  Your 
answer  will  be  helped  by  reference  to  the  next  problem. 

4.  Burn  several  different  substances  as  starch,  sugar,  bread,  cake, 
nuts,  and  meat  in  closed  jars.  Test  contents  of  jars  with  lime- 
water.  W^hat  do  you  conclude  was  present  in  these  substances? 
How  do  you  know?  What  other  substance  is  given  off  when 
these  materials  burn?  Touch  the  jars.  What  does  this  suggest 
with  reference  to  energy  released? 


Problein  42 :  To  prove  that  growing  seeds  oxidize  food. 

Materials.  —  Two  Erlenmeyer  flasks,  rubber  stopper,  soaked 
peas,  blotting  paper. 

Method  1.  —  Put  soaked  blotting  paper  in 
each  of  two  flasks  and  place  an  equal  number  of 
peas  in  each  flask.     Cork  one  flask  only. 

Observations.  —  Watch  for  evidences  of  growth 
in  each  flask.  Note  carefully  j ust  what  happened 
to  the  peas  in  the  closed  flask ;  in  the  open  flask. 

Conclusion.  —  Remembering  what  you  have 
learned  in  your  previous  experiments,  how  would 
you  account  for  what  you  see  ? 

Method  2.  —  Now  test  the  air  in  the  closed 
flask  v*^ith  limewater.  (Or  a  bottle  containing 
limewater  may  be  placed  in  the  jar  at  the  be- 
ginning of  the  experiment.     See  accompanying 

The    Inclosed      fng-vire  ) 
Bottle  contains         &        •/ 

Limewater.  Observations.  —  What  happens? 


PROBLEM  45  67 

Conclusion.  —  1.  How  do  you  account  for  the  presence  of 
carbon  dioxide  in  the  closed  flask? 

2.  Why  did  the  seeds  in  the  open  flask  grow? 

3.  From  what  source  did  the  seeds  get  theii-  energy  to  grow  in 
the  open  flasl;:  ? 

General  Conclusion.  —  Write  up  a  brief  statement,  using  proof 
to  show  that  energy  is  locked  up  in  food  and  that  it  can  be  released 
and  used  only  by  oxidation. 

Problem  43 :  To  study  the  fruit  of  the  corn  plant. 

Materials.  —  Ripe  corn  on  the  cob. 

Method.  —  Compare  the  ripe  corn  on  the  cob  with  the  picture 
on  page  67  of  your  Civic  Biology  and  with  specimens  shown  by 
the  teacher. 

Observations.  —  What  differences  are  there  between  the  young 
and  the  old  specimens? 

Conclusion.  —  Is  the  ear  of  corn  a  single  fruit  or  a  bunch  of 
fruits?     Give  reasons  for  your  answer. 

Problem  44:  To  study  the  structure  of  a  grain  of  com. 

Materials.  —  Entire  soaked  corn  grains  and  some  cut  lengthwise 
at  right  angles  to  the  flat  surface.     Figure  page  66,  Ciiic  Biology. 

Method  and  Observations.  —  In  an  entire  corn  grain  find  a 
light-colored  area  on  one  side.  This  marks  the  posit ioii  of  the 
embryo. 

In  a  grain  cut  lengthwise  at  right  angles  to  the  flat  side  find  the 
embryo.  Describe  its  shape,  position,  and  relative  size  compared 
with  the  rest  of  the  corn  grain. 

Note.  — The  area  outside  of  the  embryo  is  known  as  the  endosperm. 

Place  iodine  on  the  surface  of  the  cut  corn  grain.  Describe 
what  happens.     Test  for  protein. 

Conclusion.  —  1.    What  nutrients  are  present  in  the  corn? 
2.    Where  are  they  found  ? 

Problem  45:  To  find  the  use  of  the  cndospevnt  of  flic  corn 
grain. 

Materials.  —  Sprouted   corn  grains,   scalpel,   and  sawdust. 


68  PLANT   GROWTH   AND   NUTRITION 

Method.  —  In  some  corn  grains  that  have  sprouted  remove  the 
endosperm.  Place  them  side  by  side  in  moist  sawdust  with  some 
normal  sprouted  grains.  Give  each  lot  of  seedlings  the  same  con- 
ditions of  water,  light,  and  air. 

Observations.  —  Watch  them  carefully  for  a  period  of  at  least  two 
weeks.  What  differences  do  you  observe  in  the  rates  of  growth  in 
the  two  lots  of  seedlings  ? 

Conclusion.  —  What  is  the  use  of  the  endosperm  to  the  corn? 

Prohlern  46 :  To  find  whether  starch  or  grape  sugar  will  dis- 
solve in  water. 

Materials.  —  Test  tubes,  starch,  grape  sugar. 

Method.  —  Shake  up  a  little  starch  with  water.  Let  it  stand 
for  a  few  minutes.  Shake  up  an  equal  amount  of  dry  grape  sugar 
in  water.     Let  it  stand  for  the  same  length  of  time  as  the  starch. 

Observations.  —  How  do  the  two  compare  in  appearance? 

NOTE.  —  A  substance  is  said  to  be  soluble  when  it  dissolves  or  entirely  disappears 
from  view  in  water  or  some  other  liquid. 

Conclusion.  —  Is  starch  or  grape  sugar  soluble  in  water? 

Problem  47 :  To  find  how  the  young  plant  makes  use  of  the 
food  supply.    Digestion. 

Method  and  Observations.  —  Wash  some  dry,  unsprouted  corn 
grains  and  test  them  for  grape  sugar.  Then  cut  some  corn  grains 
that  have  just  begun  to  germinate  lengthwise  through  the  embryo 
and  test  for  grape  sugar.  Look  for  changes  in  color  between  the 
embryo  and  endosperm. 

NOTE.  —  Under  certain  conditions  when  starch  is  changed  to  grape  sugar  it  is 
said  to  have  been  digested.  In  the  corn  plant  this  is  accomplished  by  a  digestive 
ferment,  or  enzyme,  called  diastase. 

What  differences  between  the  unsprouted  and  sprouted  corn 
do  you  find? 

Conclusion.  —  1.  What  happens  to  the  starch  when  corn 
sprouts  ? 

2.  What  causes  this  change? 

3.  Of  what  use  would  this  change  in  the  form  of  the  food  supply 
be  to  the  young  plant? 


PROBLEM   50  CO 

4.  Why  is  it  necessary  that  plants  dijiicsi  starchy  and  other 
foods  ? 

Vrohleni  4S :  What  changes  take  place  in  starchy  foods  in 
the  mouth?     (Demonstration.) 

Materials. ' —  Cracker,  Fehling's  solution,  Bunsen  burner,  test 
tube. 

Method  and  Observations.  —  Chew  an  unsweetencHl  cracker 
slowly.  Note  any  change  in  taste.  Test  some  of  the  unchewetl 
cracker  with  Fehling's  solution.  Result?  Place  a  little  of  the 
chewed  cracker  and  saliva  in  a  test  tube,  add  Fehling's  solution, 
and  heat.     What  happens  ? 

Conclusion. — What  happens  to  starchy  foods  in  the  mouth? 
Of  what  use  might  this  be  to  man  ? 

Problem  49:  Conditions  necessary  for  the  action  of  diastase. 

Materials.  —  Test  tubes,  diastase,  starch  paste,  ice,  Fehling's 
solution,  Bunsen  flame,  test-tube  rack. 

Method.  —  Place  a  little  diastase  in  three  test  tubes  containing 
starch  paste.  Label  them  1,  2,  and  3.  Place  1  in  the  icebox  on 
the  ice ;  boil  the  contents  of  2  and  then  place  it  with  3  in  the  test- 
tube  rack  in  the  laboratory. 

Observations.  —  After  24  hours  test  the  contents  of  each  of  the 
three  tubes  for  sugar.     Has  digestion  taken  place  in  all  tubes? 

Note.  —  Diastase  has  thus  been  shown  to  act  only  under  certain  conditions. 
Water  must  be  present  and  a  certain  temperature.  Its  action  may  be  prevented 
by  extreme  heat.     In  these  respects  it  acts  as  if  it  were  like  a  living  substance. 

Conclusion.  —  What  conditions  are  most  favorable  to  digestion 
by  the  diastase  ? 

Note.  —  Pure  diastase  must  be  used  for  this  experiment.  Mo.st  diastase  prepa- 
rations contain  grape  sugar. 

Problem  50:  What  is  the  reason  for  digestion  of  starch  in 
the  corn  grain  ? 

Materials.  —  Funnels,  filter  paper,  starch,  sugar,  beaker. 

Method. —  Take  two  fimnels,  place  filter  papers  witliin  each. 
In  one  funnel  place  a  mixture  of  starch  antl  water,  in  a  second  a 


70  PLANT  GROWTH   AND   NUTRITION 

solution  of  grape  sugar  and  water.  Collect  in  a  beaker  the  filtrates 
(the  substances  that  pass  through  the  filter  paper). 

Observations.  —  Do  the  contents  of  both  funnels  pass  through 
the  filter  papers?  Test  the  contents  of  the  vessels  into  which 
the  contents  of  the  first  and  second  filter  have  passed,  the  first 
with  iodine,  the  second  with  Fehling's  solution.     What  happens? 

Conclusion.  —  1.  If  the  corn  seedling  absorbs  or  takes  in  food, 
what  forms  must  it  be  in?     How  do  you  know? 

2.  What  is  the  purpose  of  digestion  in  plants? 

Problem   Questions 

1.  What  results  from  the  fertilization  of  a  flower? 

2.  What  are  the  uses  of  the  various  parts  of  a  plant  embryo? 

3.  How  is  an  embryo  protected?  (Think  of  a  corn  or  bean 
embryo.) 

4.  What  are  nutrients? 

5.  How  could  you  detect  starch,  protein,  grape  sugar,  or  oil  in 
any  substance? 

6.  Why  would  it  be  necessary  to  mash  up  or  boil  a  substance 
which  you  wished  to  test  for  starch? 

7.  How  could  you  detect  the  presence  of  mineral  matter  in  a 
bean  ? 

8.  How  could  you  test  for  the  presence  of  water  in  a  substance? 

9.  Name  five  substances  containing  starch ;  fat ;  protein. 

10.  What  conditions  are  necessary  to  make  an  embryo  grow? 

11.  Why  is  air  necessary?     Explain  just  what  air  does. 

12.  Could  a  plant  do  work  without  oxygen?     Explain. 

13.  What  happens  as  a  re'sult  of  oxidation  of  wood  or  coal? 

14.  What  happens  when  oxidation  takes  place  in  the  body? 

15.  How  could  you  prove  that  plants  and  animals  use  oxygen 
for  the  same  purpose? 

16.  What  is  an  ear  of  corn?  A  grain  of  corn?  Explain  with 
reference  to  diagrams  in  your  Civic  Biology,  pages  67,  69. 

17.  How  and  where  is  food  stored  in  a  corn  grain? 

18.  A  corn  grain  grows.  How  can  it  get  its  food  so  as  to  make 
use  of  it?  , 


REFERENCE   BOOKS  71 

19.   Will    starch    pass    through    a    filter    paper?     Will    sugar? 
How  can  you  explain  this? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  V.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chap.  VI.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  VI.     American  Book  Company. 

Corbett,  The  Propagation  of  Plants.  Farmers'  Bulletin  No.  157,  U.  S.  Depart- 
ment of  Agriculture. 

Ganong,  The  Living  Plant.     Henry  Holt  and  Company. 

Kerner  (translated  by  Oliver),  Natural  History  of  Plants.  Henry  Holt  and  Com- 
pany, 4  vols.     Vol.  II,  Part  2. 

Lubbock,  Flowers,  Fruits,  and  Leaves.     The  Macmillan  Company. 

MacDougal,  Experimental  Plant  Physiology.     Longman.s,  Green  and  Company, 

Sargent,  Corn  Plants.     Houghton  Mifflin  Company. 

Schimper,  Plant  Geography  on  a  Physiological  Basis.     Frowde,  London. 

Soraurer,  A  Popular  Treatise  on  the  Physiology  of  Plants.  Longmans,  Green  and 
Company. 


VI.   THE  ORGANS   OF  NUTRITION  IN  PLANTS  —  THE 
SOIL  AND   ITS   RELATION   TO   THE   ROOTS 

Problem.—  What  a  plant  tahes  from  the  soil  and  how  it  gets 
it, 

(a)  What  determines  the  direction  of  growth  of  roots? 

(b)  How  is  the  root  hiiilt  ? 

(c)  How  does  a  root  absorb  water  ? 

(d)  What  is  in  the  soil  that  a  root  might  tahe  out  ? 

(e)  Why  is  nitrogen  necessary,  and  how  is  it  obtained  ? 

Laboratory  Suggestions 

Demonstration.  —  Roots  of  bean  or  pea. 

Demonstration  or  home  experiment.  —  Response  of  root  to  gravity  and 
to  water.     What  part  of  root  is  most  responsive  ? 

Laboratory  work.  —  Root  hairs,  radish  or  corn,  position  on  root,  gross 
structure  only.     Drawing. 

Demonstration.  —  Root  hair  under  compound  microscope. 

Demonstration.  —  Apparatus  illustrating  osmosis. 

Demonstration  or  a  home  experiment.  —  Organic  matter  present  in  soil. 

Demonstration.  —  Root  tubercles  of  legume. 

Demonstration.  —  Nutrients  present  in  some  roots. 

To  THE  Teacher.  —  The  principle  of  osmosis,  one  of  the  most  difficult  concepts 
the  child  has  to  grasp,  is  the  keynote  of  the  work  of  this  chapter.  The  practical 
side  is  seen  in  the  reference  to  crop  rotation,  nitrogen-fixing  bacteria,  and  the  like. 
Every  educated  person  should  be  informed  on  the  principles  underljdng  the  work  of 
the  bacteria  of  decay  and  the  nitrogen-fixing  bacteria  in  soils.  The  root  as  an  organ 
of  absorption  should  be  demonstrated  fully,  mth  individual  laboratory  work  on 
root  hairs  as  structural  organs,  so  that  the  child  may  realize  the  extreme  delicacy  of 
these  absorbing  organs. 

Pi'oblem  51 :  To  find  out  the  structure  of  roots. 

Materials.  —  Bean,  pea,  or  corn  seedlings  grown  in  sawdust. 

Method  and  Observations.  —  In  the  roots  of  a  bean  seedling 
notice  the  main  root.  From  what  part  of  the  embryo  did  this 
come?     Branches  of  this  main,  or  primary  root,  are  called  sec- 

72 


PROBLEM   53  73 

ondary  roots.     Notice  the  direction  taken  by  the  main  root  ;  l)y 
the  secondary  roots;  by  the  rootlets. 

Conclusion.  —  Remembering  that  a  tall  stem  is  sent  into  the 
air : 

1.  What  is  one  reason  for  the  wide  spreading  of  roots? 

2.  What  might  be  one  other  use  of  roots  to  a  plant? 

Problem  52:  To  determine  the  influence  of  gravity  on  the 
direction  of  growth  of  roots. 

Materials.  —  Radish  or  mustard  seeds,  pocket  garden.^  Dia- 
gram page  72,  Civic  Biology. 

Method.  —  Grow  radish  or  mustard  seeds  in  a  pocket  garden 
placed  on  edge  until  the  roots  are  a  half  inch  long;  then  turn  it 
on  another  edge  and  examine  again  after  24  hours.  Repeat  after 
another  24  hours. 

Observations.  —  Which  part  of  the  root  grows  down  each  time 
the  garden  is  turned  ? 

NOTE.  —  The  force  which  pulls  objects  toward  the  center  of  the  earth  is  known 
as  gravity. 

Conclusion.  —  1.  What  causes  roots  to  turn  downward? 
2.  What  part  of  a  root  is  most  influenced  by  this  force? 

Problem  53:  To  find  the  effect  of  water  on  the  growth  of 
roots. 

Materials.  —  Radish  or  mustard  seeds,  sponge. 

Method.  —  Plant  soaked  mustard  or  radish  seeds  on  the  outer 
side  of  a  moist  sponge.  Suspend  the  sponge  under  a  bell  jar  in 
moderate  temperature. 

Observations.  —  What  happens  to  the  roots? 

Conclusion.  —  1.  What  effect  does  water  have  on  the  direc- 
tion of  growth  of  roots? 

2.  Which  influence  is  more  powerful,  moisture  or  gravity? 

1  A  pocket  garden  may  be  made  as  follows:  (let  a  ooupio  of  4  X  ')  nouativp 
plates,  clean  them,  and  cut  five  pieces  of  blotting  paper  about  i  inch  sinallor  than 
the  glasses.  Lay  the  blotters  on  one  of  the  plates,  and  cut  four  J-inch  strips  of 
wood  so  as  just  to  fit  on  the  glass  outside  the  l)l()tters.  Moisten  the  l)lotters, 
place  some  well-soaked  seeds  of  mustard,  barley,  or  radish  on  them,  fover  the 
seeds  with  the  other  glass,  and  bind  the  glasses  together  with  bicycle  tape. 


74  SOIL   AND   ITS   RELATION   TO   ROOTS 

Pt'ohle^n  54:  To  study  the  structure  and  purpose  of  root 
hairs. 

Materials.  —  Radish  or  mustard  seeds,  blotting  paper,  Syracuse 
watch  glasses,  thin  glass  plates,  glass  slide,  cover  slip,  microscope. 
Diagrams  pages  74,  75,  Civic  Biology. 

Method.  —  Grow  radish  or  mustard  seeds  on  blue  blotting  paper 
in  Syracuse  watch  glasses,  covering  each  watch  glass  with  a  thin 
glass  plate. 

Observations.  —  Describe  the  structures  you  see  growing  from 
the  roots.  These  are  called  root  hairs.  Where  are  they  the 
longest?     Where  the  most  abundant? 

Place  a  radish  or  mustard  seedling  on  a  glass  slide.  Mount 
in  a  drop  of  water  and  cover  with  a  cover  slip.  Examine  with 
the  low  power  of  a  microscope.  What  can  you  say  of  the  thick- 
ness of  their  walls?  Of  how  many  cells  does  a  root  hair  seem  to 
consist  ? 

If  the  root  were  covered  with  these  thin-walled,  delicate  struc- 
tures, what  effect  would  they  have  upon  the  absorbing  surface  of 
the  root  ? 

Conclusion.  —  1.  Tell  what  you  believe  to  be  the  purpose 
(function)  of  root  hairs.     Give  good  reasons. 

2.  Why  should  the  wall  of  a  root  hair  be  thin? 

Drawing.  —  A  seedling  showing  position  of  root  hairs. 

Problem  55:  To  discover  how  fluids  travel  through  roots 
and  stems. 

Materials.  —  Carrot  or  parsnip,  iodine,  red  ink,  scalpel,  micro- 
scope. 

Method.  —  Cut  a  cross  section  through  a  fleshy  root  (carrot  or 
parsnip)  and  dip  in  iodine.  Also  place  sprouting  parsnips  in  red 
ink  for  two  or  three  days,  then  cut  cross  and  longitudinal  sections. 

Observations.  —  In  a  stained  cross  section  note  the  cortex 
(outer  part)  less  deeply  stained  than  the  wood  (the  inner  part). 

To  THE  Teacher.  —  Excellent  demonstration  material  may  be  obtained  by- 
placing  celery  stems  in  red  ink.  Asparagus  also  shows  well.  Several  different  types 
of  stems  might  be  shown  to  bring  out  differences  in  dicotyledonous  and  monocoty- 
ledonous  stem  structure.  Our  next  experiment  will  show  us  how  the  fluid  gets  from 
the  outside  to  the  inside  of  the  root. 


PROBLEM   5G 


» 


Hmi^IH 


Find  little  cores  of  wood  extending  out  through  the  cortex  into  the 
rootlets.  This  so-called  central  cylinder  is  nmde  up  of  bundles  of 
tubelike  cells.  The  cells  collectively  form  the  Jlhrovascular 
bundles. 

In  the  picture  of  the  cross  section  (see  page  74,  Civic  Biology) 
find  (1)  the  cortex,  (2)  the  central  cylinder,  and  (3)  the  root  hairs. 
How  many  cells  are  in  a  root  hair?  From  what 
part  of  the  root  do  the  root  hairs  grow  ? 

Place  some  bean  or  corn  seedlings  in  red  ink. 
Allow  them  to  remain  in  the  sun  for  a  few  hours 
and  then  examine  the  stem  and  leaves  carefully. 
What  has  happened? 

Cut  a  cross  section  of  one  of  the  above  stems. 
Which  part  of  the  root  and  stem  shows  the  pres- 
ence of  red  ink?  Examine  free-hand  sections 
under  the  microscope. 

Conclusion.  —  By  what  path  do  fluids  pass 
up  the  root  and  stem? 

Proble^n  56:  To  find  out  how  root  hairs 
absorb  soil  water. 

Materials.  —  Egg  or  glass  test  tube  (large), 
celloidin,  sealing  wax,  glass  tubing,  thistle  tube. 

Method.  —  To  make  an  artificial  root  hair 
we  may  take  either  an  egg,  or  a  celloidin  cell, 
which  is  made  by  pouring  a  little  thin  celloidin 
into  a  clean  test  tube,  revolving  the  tube 
rapidly,  and  then  carefully  removing  the  film 
of  celloidin  which  has  been  formed  within  the 
tube.  With  care  a  nearly  uniform  artificial 
membrane  will  have  been  formed  within  the 
tube.  This,  when  removed,  may  be  filled  with 
glucose  solution,  or  any  dense  material  that 
will  dissolve  in  water.  Tie  the  ui^i^er  end  of 
it  tightly  over  the  wide  end  of  a  thistle  tube  and  insert  the 
bag  in  a  dish  of  water. 

If  an  egg  is  to  be  used,  break  the  shell  at  one  end  and  remove 


Appauatus  to  show 
Osmosis. 


76  SOIL  AND   ITS   RELATION   TO   ROOTS 

part  of  it  so  carefully  as  not  to  tear  the  membrane  directly  under 
the  shell,  then  break  the  other  end,  insert  a  glass  tube  in  it, 
and  cement  the  tube  in  place  with  sealing  wax.  Then  place  the 
egg  with  the  exposed  membrane  in  water. 

Observations.  —  Are  there  any  changes  in  the  level  of  the 
liquid  in  the  tube? 

Note.  —  The  process  by  which  two  fluids  or  gases,  separated  by  a  membrane, 
pass  through  the  membrane  and  mingle  is  called  osmosis.  The  greater  flow  is  usu- 
ally from  the  less  dense  toward  the  denser  medium. 

Test  the  water  in  the  jar  (if  you  used  glucose  in  your  artificial 
cell)  to  see  if  glucose  passed  through  the  membrane. 

Conclusion.  —  1.  Explain,  using  one  of  the  above  experiments 
as  a  basis,  how  osmosis  takes  place. 

2.  How  do  root  hairs  take  in  soil  water? 

3.  What  might  help  force  liquids  up  the  stem  of  the  plant? 

Prohlern  57 :  To  determine  what  hind  of  substances  will  pass 
through  a  7}%embrane. 

Materials.  —  Glass  jar,  two  thistle  tubes,  membrane  or  parch- 
ment paper,  starch,  grape  sugar,  iodine,  Fehling's  solution,  test 
tubes. 

Method.  —  Fill  two  thistle  tubes,  one  with  glucose  and  water, 
the  other  with  starch  and  water ;  tie  membranes  tightly  over  each. 
Wash  carefully  to  remove  all  starch  or  sugar  from  outside  of  tubes. 
Then  place  each  in  a  jar  half  filled  with  water.  After  24  hours, 
test  contents  of  the  jars,  one  for  starch  and  the  other  for  grape 
sugar.     (See  low^er  figure,  page  100,  Civic  Biology.) 

Observations.  —  Notice  if  any  change  has  taken  place  inside 
the  thistle  tubes.  What  changes  take  place  after  testing  the 
contents  of  the  jar? 

Conclusion.  —  1.  Does  starch  or  sugar  pass  through  a  mem- 
brane by  osmosis? 

2.  Can  you  make  a  generalization  to  cover  soluble  and  insolu- 
ble substances? 

NOTE.  —  Osmosis  or  exchange  of  gases  will  also  take  place  through  a  membrane. 
If  carbon  dioxide  and  oxygen  gases  were  separated  by  a  membrane,  they  would 
tend  to  pass  through  the  membrane  and  mingle  with  each  other. 


PROBLEM  59 


77 


Problem  5S :  To  test  organic  material  in  soil. 

Materials.  —  Samples  of  different  kinds  of  soils,  balance  and 
weights,  Bunsen  burner,  pieces  of  tin. 

Method.  —  Obtain  a  small  quantity  of  vegetable  mold,  rich  gar- 
den soil,  and  soil  from  a  sandy  road.  Allow  each  lot  to  remain  for 
several  days  in  a  dry  place  so  as  to  remove  surplus  water.  Then 
take  eight  ounces  of  vegetable  mold  from  a  forest,  eight  ounces  of 
rich  soil  from  a  garden,  and  the  same  amount  from  a  sandy  road. 
Weigh  carefully,  place  each  on  a  piece  of  tin  or  sheet  iron,  and  heat 
red-hot  for  at  least  20  minutes.     Now  reweigh  each  sample. 

Observations.  —  Tabulate  results  as  follows  : 


VerfetciLlc 

I^icliSoil 

TVccrreiv 
Soil 

Origincd  Weight 

V^IgKt  after  turning 

Loss  iivV7eigKt 

Conclusion.  —  1.  How  do  you  account  for  the  losses  in  weight  ? 
2.  Might  there  be  a  loss  of  more  than  one  substance  to  account 
for  this  ? 

Problem  59 :  To  find  what  kind  of  soil  holds  water  best. 

Materials.  —  Gravel,  sand,  clay,  loam,  leaf  mold,  wide-mouth 
bottles,  balance  and  weights,  one-hole  rubber  st()i)pers,  glass 
tubing. 

Method.  —  Weigh  out  an  equal  amount  of  gravel,  saiul,  clay, 
rich  loam,  leaf  mold,  and  one  quarter  as  nuich  by  weight  of  dry 
leaves.  Prepare  six  bottles,  cut  out  the  bottoms,  i)lacing  the 
various  materials  in  the  bottles  as  shown  in  the  lowoi-  figure,  page 
78,  Civic  Biology.  Into  each  bottle  now  i)our  slowly  owv  pint 
of  water. 

Measure  the  amount  of  water  that  drips  through  each  bottle. 


78 


SOIL   AND   ITS   RELATION   TO   ROOTS 


Observations.  —  Tabulate  the   exact   amount   of  water  left  in 
the  soil  in  each  case. 


0/    VT'citer 

Gravel 

San-d 

CI  cry 

ZrOCCHV 

Lect/ 

Leaves 

-A.ololeoL 

d  civjrflvt 

Left  in  Soil$ 

Conclusion.  —  1.  Of  what  use  is  the  forest  covering  of  leaf 
mold  ? 

2.  Which  kinds  of  soils  would  be  most  favorable  for  crops  and 
why? 


Problem  60 :  What  do  plants  take  out  of  the  soil  ? 

Materials.  —  Glass  jars,  distilled  water,  nutrient  solution,  corn 
seedlings. 

Method.  —  Partly  fill  five  jars,  the  first  with  distilled  water, 
the  second  with  nutrient  solution  ^  without  potassium  nitrate,  a 
third  with  nutrient  solution  without  calcium  phosphate,  the 
fourth  with  nutrient  solution  without  ferric  chloride,  and  a  fifth 
with  nutrient  solution.  Place  in  the  jars  corn  seedlings  with  their 
roots  in  the  liquids.  Keep  them  under  observation  for  two  or 
more  weeks. 

^  A  nutrient  solution  known  as  Sach's  solution  may  be  made  as  follows : 

Potassium  Nitrate         1.00  gram 

Sodium  Chloride 0.50  gram 

Calcium  Sulphate 0.50  gram 

Magnesium  Sulphate 0.50  gram 

Calcium  Phosphate 0.50  gram 

Ferric  Chloride 0.005  gram 

Distilled  Water 1000.00  grams 

Add  the  ferric  chloride  at  the  time  the  solution  is  to  be  used,  by  adding  a  drop  or 
so  to  the  solution  in  the  bottle  used  for  the  seedlings. 


PROBLEM   ()2  79 

Observations.  —  In  which  does  the  most  vip;oious  growth  lake 
place? 

Conclusion.  —  1.  What    materials    do    plants    take    in    with 

water  ? 

2.  What  is  the  source  of  these  materials? 
t 

Problem  61 :  How  are  root  hairs  able  to  take  mineral  matter 

out  of  the  soil  ? 

Materials.  —  Vigorous  bean  or  corn  seedling,  test  tubes  on  base, 
phenolphthalein  solution. 

Method.  —  To  a  solution  of  phenolphthalein  add  drop  by  drop 
a  little  strong  nitric  acid.     Notice  what  happens. 

Place  in  another  tube  containing  a  phenolplithalein  solution 
(which  should  be  almost  neutral)  a  growing  seedling.  Leave 
overnight  and  then  observe.  Compare  with  a  control  tube  con- 
taining phenolphthalein. 

Observations.  —  Compare  the  color  in  the  control  tube  with  the 
color  in  the  tube  containing  the  seedling. 

Compare  the  tube  to  which  acid  was  added  with  that  containing 
the  seedling. 

Conclusion.  —  L  What  substance  is  given  off  by  roots? 

2.  What  effect  might  this  have  upon  certain  minerals  in  the 
soil?     (Try  the  effect  on  a  bit  of  limestone.) 

Problem  62 :  What  are  root  tubercles  and  what  is  their  use? 

Materials.  —  Clover  or  bean  plants.  Diagram  page  81,  Civic 
Biology. 

Method.  —  Remove  and  wash  carefully  the  roots  of  a  clover  or 
bean  plant.  Place  in  a  test  tube  with  a  base  for  laboratory 
study. 

Observations.  —  Do  you  find  little  lumps  or  tubercles  on  the 
roots?     Locate  exactly. 

Note.  —  Root  tubercles  are  small  knobliko  structures  which  develop  on  tlie 
roots  of  leguminous  plants  (clover,  alfalfa,  peas,  beans,  cowpeas,  etc.)-  In  these 
tubercles  develop  millions  of  little  plants  called  nitrifying  bacteria.  These  plants 
alone  of  all  others  are  able  to  take  nitrogen  from  the  air  and  to  combine  it  witli 
certain  mineral  substances  in  the  soil  to  form  nitrates.  In  this  form  it  is  taken 
up  by  plants. 


80 


SOIL   AND   ITS   RELATION   TO   ROOTS 


Conclusion.  —  1.  By  what  means  do  plants  get  a  fresh  supply 
of  nitrogen? 

2.  Wh}'  do  peas  and  beans  contain  so  much  protein  food? 

Problem  63 :   What  is  crop  rotation  and  what  is  its  use  ? 

Note.  —  a  regular  order  of  crops  in  which  some  nitrogen-fixing  crops  are  fol- 
lowed by  plants  which  take  nitrogen  from  the  soil  is  known  as  crop  rotation. 

Method.  —  Suppose  on  four  farms  crops  are  planted  each  year 
as  follows : 


IsT  Year 

2d  Year 

3d  Year 

4th  Year 

5th  Year 

6th  Year 

1.    Clover 

Wheat 

Tobacco 

Clover 

Wheat 

Beans 
and 
Peas 

2.    Corn 

Rye 

Wheat 

or 

Oats 

Grass 

Clover 

Wheat 

3.    Corn 

Oats 

Wheat 

Grass 

Potatoes 

Corn 

4.    Clover 

Corn 

Corn 

Clover 

and 

Grass 

Clover 

and 

Grass 

Clover 

and 

Grass 

Conclusion. —  1.  Which  of  the  above  crops  are  nitrogen  pro- 
ducing?    Nitrogen  taking? 

2.  Which  of  the  four  farms  gets  the  most  out  of  the  soil  ?     Why  ? 

3.  Explain  what  is  meant  by  crop  rotation.  Why  is  it  of  great 
importance  ? 

Problem  64 :  What  roots  are  useful  as  food  ? 

Method.  —  Test  as  many  different  roots  as  possible  for  the 
presence  of  nutrients. 

Make  a  list  of  some  roots  used  by  man  as  food  and  some  used 
by  animals  other  than  man. 

Conclusion.  —  1.   What  roots  are  most  useful  to  man  as  food? 

2.   What  roots  are  used  by  animals  other  than  man  ? 


PROBLEM   QUESTIONS  81 

Problem  (Questions 

1.  Why  is  the  root  call('<l  I  lie  iiioulh  of  a  plant? 

2.  From  where  would  wat(M'  come  tiial  roots  take  in? 

3.  How  could  water  pass  from  the  root  hairs  into  the  woody 
center  of  a  root? 

4.  What  has  osmosis  to  do  with  plant  mitrition  ? 

5.  What  has  osmosis  to  do  with  our  own  nutrition  ? 

6.  How  do  you  know  gravity  affects  roots? 

7.  Why  might  forests  have  an  effect  upon  the  climate  of  a 
given  part  of  the  country? 

8.  Why  is  it  important  not  to  cut  down  trees  near  the  sources 
of  our  rivers  ? 

9.  What  do  roots  have  to  do  with  the  holding  and  distribu- 
tion of  water? 

10.  Why  do  peas  and  beans  contain  a  large  amount  of  nitroge- 
nous food  ? 

11.  Very  much  larger  yields  are  had  from  crops  in  some  pai'ts 
of  the  world  than  in  others.     How  do  you  account  for  this? 

12.  Why  do  some  farmers  plant  beans  or  cowpeas  in  their 
corn  fields  between  the  hills  of  corn?  Is  the  custom  good  or  bad? 
Explain. 

13.  What  plants  store  food  in  their  roots? 

14.  How  do  foods  become  stored  in  roots? 

15.  For  what  reason  should  a  city  boy  or  girl  study  about 
roots  ? 

16.  Why  do  farmers  plant  seeds  a  short  distance  below  the  sur- 
face of  the  ground? 

17.  Why  do  farmers  cultivate  (break  up)  the  soil? 

18.  What  is  the  reason  for  placing  dead  leaves  or  other  dead 
organic  matter  on  the  surface  of  the  ground  early  in  th(^  winter? 

19.  What  is  weathering?     How  does  it  affect  rocks? 

20.  Find  the  factors  that  influence  the  making  of  soil. 

21.  Why  should  plants  not  be  crowded  togetlu>r  in  the  soil? 

22.  What  kinds  of  soil  retard  evaporation?     Why? 

23.  Why  do  we  hear  so  much  nowadays  of  going  back  to  the 
soil  ?    What  does  this  term  mean  ? 

HUNTER   LAB.    PROB.  —  G 


82  SOIL   AND   ITS   RELATION   TO   ROOTS 


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Coulter,  Barnes,  and  Cowles,  A   Textbook  of  Botany,  Part  II.     American  Book 

Company. 
Detmer-Moor,  Practical  Plant  Physiology.     The  Macmillan  Company. 
Duggar,  Plant  Physiology.     The  Macmillan  Company. 
Fairchild,  The  New  Hope  of  Farmers.     World's  Work,  July,  1906. 
Field,  Scientific  Agriculture.     Report  of  the  Rhode  Island  Board  of  Agriculture, 

1896. 
Fippin,  The  Soil,  Its  Use  and  Abuse.     Cornell  Reading  Course  Bulletin,  Oct.  15, 

1911. 
Goflf  and  Mayne,  First  Principles  of  Agriculture.     American  Book  Company. 
Goodale,  Physiological  Botany.     American  Book  Company. 
Gray,  Structural  Botany,  pp.  27-39,  56-64.     American  Book  Company. 
Green,  Vegetable  Physiology,  Chaps.  V,  VI.     J.  and  A.  Churchill. 
Hall,  The  Soil  as  a  Battle  Ground.     Harpers'  Magazine,  October,  1910. 
Hilgard,   Soils,   their  Formation.     The   Macmillan   Company. 
Hunt,   The  Importance  of  Nitrogen  in  the  Growth  of  Plants.     Cornell  University 

Experiment  Station  Bulletin,  No.  247,  June,   1907. 
Huntington,    Beans   and   Peas    for    Fertilizer.     Long   Island   Agronomist,    No.    8, 

Nov.  3,  1909. 
Jenkins,  Keeping  up  Fertility.     Garden  Magazine  —  Farming,  June,   1910. 
Kerner-Oliver,  Natural  History  of  Plants.     Henry  Holt  and  Company. 
MacDougal,   Plant  Physiology.     Longmans,   Green  and   Company. 
Martin,  The  Work  of  the  Brook.     Cornell  University  Nature  Study  Quarterly,  No.  5, 

June,  1900. 
Massey,  Practical  Farming.     A.  C.  McClurg  and  Company. 

Moore,  The  Physiology  of  Man  and  Other  Animals.     Henry  Holt  and  Company. 
Moore,  Soil  Inoculation.     Century  Magazine,  October,  1904. 
Murray,  Soils  and  Manures.     D.  Van  Nostrand  and  Company. 
Pfeffer,  The  Physiology  of  Plants.     Clarendon  Press. 
Seton,  Gophers  as  Soil  Formers.     Century  Magazine,  June,  1904. 


IIEFEKENCE   BOOKS  83 

Stevens,  Introduction  to  Botany,  pp.  ;dl-44.      D.  ('.  Heath  and  CoinpiuiN . 
Tarr,  .1  Handful  of  Soil.     Cornell  University  Nature  Study  Quarterly,  \o.  2,  (Octo- 
ber, 1899. 
Tarr,  A  Summer  Shower.     Cornell  University  Bulletin  No.  1,  .lunc,  1S99. 
Warren,    Elements   of  Agriculture.     The    Macniillan    ('onipany. 
Wilkinson,  Practical  Agriculture.     American  Book  Company. 


VII.   PLANT   GROWTH   AND   NUTRITION  —  PLANTS 

MAKE   FOOD 

Problem.  —  Wlwre,  when,  and  how  green  plants  make  food. 
{a)  How  and  why  is  inoisture  given  off  from  leaves? 

(b)  What  is  the  reaction  of  leaves  to  light  ? 

(c)  What  is  made  in  green  leaves  in  the  sunlight  ? 

id)  What  by-prodiiets  are  given  off  in  the  above  process  ? 
(e)    Other  functions  of  leaves. 

Laboratory  Suggestions 

Dernonstration.  —  Water  given  off  by  plant  in  sunlight.     Loss  of  weight 
due  to  transpiration  measured. 
Laboratory  exercise.  — 

(a)  Gross  structure  of  a  leaf. 

(6)  Study  of  stoma  and  lower  epidermis  under  microscope. 

(c)  Study  of  cross  section  to  show  cells  and  air  spaces. 
Demonstration.  —  Reaction  of  leaves  to  light. 
Demonstration.  —  Light  necessary  to  starch  making. 
Demonstration.  —  Air  necessary  to  starch  making. 
Demonstration.  —  Oxygen  a  by-product  of  starch  making. 

To  THE  Teacher.  —  In  this  chapter  experimental  work  may  be  made  to  carry- 
almost  the  entire  plan  of  the  chapter.  That  plants  make  food  out  of  raw  food 
materials  may  be  demonstrated  by  a  series  of  logical  experiments  which  leave  no 
doubt  as  to  the  steps  taken  or  the  factors  involved  in  this  wonderful  process.  That 
the  whole  world  depends  upon  the  process  of  photosynthesis  is  well  known.  A 
concept  of  what  the  process  is  and  what  it  does  for  mankind  should  be  known  by 
every  pupil  when  he  has  finished  the  exercises  which  follow.  Laboratory  problems 
having  rigid  adherence  to  the  logical  sequence  of  events  which  culminate  in  food 
making  and  food  storage  in  the  leaf,  will  result  in  increased  power  on  the  part  of 
the  pupil  and  a  beginning  of  appreciation  of  what  a  developed  problem  really 
means.  To  the  critic  who  would  object  to  so  much  time  given  to  the  processes 
involved  in  photosynthesis  we  would  say :  starch  making  and  food  making  may 
be  tied  up  in  a  vital  manner  to  the  interest  of  the  city  child  by  drawing  atten- 
tion to  the  economic  importance  of  cereal  and  other  staples  furnished  man  by 
plants,  and  by  making  clear  the  tremendous  importance  of  green  plants  in  the  role 
of  food  makers  on  the  earth.     (See  Chapter  XI,  Civic  Biology.) 

84 


PROBLEM   ()7  85 

Prohleni  65 :  To  prove  that  water  is  <^ivpn  off  hy  a  ^rccn  ])Iant. 

Materials.  —  Bell  jar,  a  j;rowin«;-  sinji;le-stcmmc(l  ^rcon  i)lant 
as   a  geranium,   rul)l)or   tissue,   l)alance. 

Method  1.  —  Cover  with  rubber  tissue  a  flower  pot  in  which  a 
vigorous  rubber  plant  or  geranium  is  growing,  so  that  only  stem 
and  leaves  are'  exposed.  Water  the  plant  prior  to  covering  with 
the  rubber  tissue.  Then  weigh  the  plant.  Record  weight. 
Then  reweigh  the  plant  after  two  or  three  hours. 

Observations.  —  What  difference  in  weight  do  you  observe? 

Method  2.  —  Water  the  plant,  tie  up  with  rubber  tissue  as  be- 
fore, and  place  under  a  bell  jar. 

Observations.  —  What  collects  on  the  inner  surface  of  the  jar? 

Conclusion.  —  1.  To  what  is  the  loss  of  weight  due? 

2.  How  and  when  does  the  water  get  out  of  the  plant? 

Note.  —  The  giving  off  of  water  in  the  form  of  vapor  through  the  leaves  is 
called  transpiration. 

Problem  66 :  Through  which  surface  of  a  leaf  does  transpir- 
ation take  place  ? 

Materials.  —  Two  rubber-plant  leaves,  vaseUne,  scales. 

Method.  —  Cover  the  upper  surface  of  one  leaf  and  the  lower 
surface  of  the  other  with  vaseline.  Vaseline  both  leaf  stalks  at  the 
end  where  the  leaves  were  broken  off.  Balance  the  leaves  exactly 
on  the  scales  and  place  in  a  sunny  place. 

Observations.  —  What  happens? 

Conclusion.  —  Through  which  surface  of  a  leaf  does  transpira- 
tion take  place  ?     How  do  you  know  ? 

Problein  67 :  To  determine  how  tJie  structure  of  a  leaf  fits  it 
for  the  work  it  has  to  do. 

Materials.  —  Entire  leaf. 

Method  and  Observations.  —  Examine  a  leaf  of  maple  or  oak. 
Notice  that  it  consists  of  two  parts  :  a  stem,  the  petiole,  and  a  l)road 
expanded  part,  the  blade.  Note,  also,  that  the  })etiole  leads  into 
a  number  of  branching  veins  which  support  the  blade.  Estimate 
the  amount  of  green  leaf  surface  in  a  plant  in  the  room  by  mult  ii)ly- 
ing  the  surface  area  of  one  leaf  by  the  number  of  leaves  on  the  plant. 


86  PLANTS   MAKE   FOOD 

Conclusion.  —  1.    What  seems  to  be  one  purpose  of  the  veins? 

2.  Remembering  that  the  veins  contain  fibrovascular  bundles, 
the  tubes  which  conduct  fluids  through  the  plant,  determine 
another  function. 

3.  How  is  the  leaf  fitted  to  receive  light?     Explain. 

Problem  6S :  To  study  the  microscopic  structure  of  a  leaf. 

Materials.  —  Leaf  of  geranium,  glycerine,  compound  microscope, 
glass  slides,  cover  glasses,  needles.  Diagram,  page  86,  Civic 
Biology. 

Method.  —  Remove  with  a  needle  a  tiny  portion  of  the  under 
surface  of  a  leaf  such  as  the  geranium,  or  Tradescantia,  mount  in 
water  or  glycerine,  and  examine  with  the  low  power  of  a  compound 
microscope. 

Observations.  —  Note  numerous  small  structures  (stomata) 
scattered  between  the  irregular  cells  of  the  epidermis. 

Note.  —  Each  stoma  is  bounded  by  two  bean-shaped  cells,  guard  cells.  By 
slight  changes  of  shape  these  control  the  size  of  the  openings  into  the  leaf. 

Study  a  cross  section  of  a  leaf  cut  through  a  stoma,  or  a  good 
chart  showing  a  cross  section  through  a  stoma  and  a  vein.  Into 
what  do  the  stomata  open  ?  The  outer  layer  of  cells,  the  epidermis, 
has  little  chlorophyll.  What  function  might  these  cells  have? 
(Look  at  the  walls.)  Beneath  the  epidermis  find  a  layer  of  long 
cylindrical  cells,  palisade  cells.  Do  these  contain  chlorophyll 
bodies?  Below  this  layer  note  a  layer  of  loosely  joined  cells,  the 
spongy  parenchyma.  Do  these  cells  contain  as  much  chlorophyll 
as  the  palisade  cells?  How  are  they  placed  with  reference  to  the 
stomata?  Look  at  the  vein.  Where  would  water  pass  through 
it? 

Conclusion.  —  Knowing  what  you  do  about  the  use  of  a 
green  leaf  to  the  plant,  determine  one  use  of  the  stomata. 

Drawings.  —  1 .  Cross  section  under  microscope.     Label  all  parts. 

2.  Part  of  lower  epidermis  showing  a  stoma. 

Problem  69 :  To  show  the  effect  of  light  on  green  leaves. 

Materials.  —  Oxalis  or  nasturtium  plants. 

Method.  —  Place  oxalis  or  nasturtium  plants  near  a  window. 


PROBLEM   71  87 

Observations.  —  After  several  days  notice  the  position  of  tlio 
•blades  of  the  leaves.     Notice  also  the  leaf  stalks. 

Conclusion.  —  What  is  the  effect  of  Hfjjht  on  leaves  and  stems? 

Note.  —  Evidently  sunlight  has  something  to  do  with  the  life  of  a  green  plant ; 
for  a  plant  growing  in  complete  darkness  is  yellow  or  bleached  (for  example,  sprout- 
ing potatoes  kept 'in  darkness).  Let  us  see  if  we  can  find  out  by  experiment  just 
what  is  the  relation  between  light  and  green  leaves. 

Problem  70:  To  determine  the  relation  of  light  to  the  ])res- 
ence  of  starch  in  a  green  leaf 

Materials.  —  Green  plant,  black  alpaca,  alcohol,  iodine. 

Method.  —  Place  any  small  green  plant  in  a  dark  room  for 
24  hours.  Then  cover  parts  of  several  different  leaves  witli 
strips  of  black  alpaca.  Expose  to  direct  sunli<;lit  for  an  hour  or 
more.  Pick  off  the  leaves  partly  covered  with  the  black  cloth, 
take  off  the  cloth,  and  place  the  leaves  in  hot  method  alcohol. 
Next  wash  the  leaves  and  place  them  in  a  solution  of  iodine. 

Observations.  —  What  happens  to  the  leaves  after  placing  them 
in  the  alcohol?  What  happens  to  the  leaves  placed  in  iodine 
solution  ? 

Conclusion.  —  1.  Why  do  we  place  the  plant  in  the  dark  at  the 
beginning  of  this  experiment? 

2.  What  effect  does  sunlight  have  upon  green  leaves?  How 
do  you  know? 

3.  What  effect  does  absence  of  light  have? 

Note.  —  Evidently  a  green  leaf  under  certain  conditions  (light  is  one)  manufac- 
tures starch.     Let  us  find  out  another. 

Problem  71 :  Is  apart  of  the  air  a  factor  in  starch  making  in 

leaves  ? 

Materials.  —  Green  potted  plant,  vaseline,  iodine,  alcohol. 

Method.  —  Treat  the  plant  as  in  the  last  problem.  After 
removing  the  plant  from  the  dark  room,  vaseline  both  sides  of  two 
or  three  leaves.  Place  the  plant  in  the  direct  sunliglit  for  an  hour 
or  two,  then  pick  off  the  vaselined  leaves  and  some  others,  marking 
them  so  that  you  may  know  them.  Place  in  liol  methyl  alcohol. 
After  the  chlorophyll  is  removed,  test  both  vaselined  and  un- 
vaselined  leaves  for  starch. 


88  PLANTS   MAKE  FOOD 

Observations.  —  Do  both  lots  of  leaves  show  the  presence  of 
starch  ? 

Conclusion.  —  What  is  another  factor  necessary  for  the  manu- 
facture of  starch  in  green  leaves? 

Prohle^n  72 :  The  need  of  chlorophyll  for  starch  maJcing. 

Materials.  —  Coleus  or  other  plant  with  variegated  leaves,  iodine, 
methyl  alcohol. 

Method.  —  Place  the  plant  in  full  sunlight  for  an  hour  or  two. 
Test  these  several  leaves  with  iodine  after  removing  chlorophyll 
with  methyl  alcohol. 

Observations.  —  Do  all  the  leaves  show  the  presence  of  starch? 
Do  all  parts  of  the  variegated  leaves  show  starch  ? 

Conclusion.  —  Is  chlorophyll  necessary  for  starch  making? 

Problem  73 :  To  consider  the  leaf  as  a  manufactory. 

Note.  —  starch  is  made  of  the  elements  carbon,  oxygen,  and  hydrogen.  We 
have  seen  that  the  roots  of  a  plant  take  up  soil  water  and  we  have  found  holes  in 
the  leaves  through  which  gases  of  the  air  might  enter.  Water  (H2O)  would  account 
for  the  hydrogen  and  oxygen,  and  carbon  dioxide  (CO2)  will  furnish  the  carbon  and 
oxygen.  Let  us  compare  the  leaf  with  a  mill  for  making  starch.  The  sun  fiirnishes 
the  energy  to  run  the  mill  and  the  chlorophyll  grains  are  the  millstones.  Carbon 
dioxide  and  soil  water  are  the  raw  products  put  into  the  mill. 

Observations.  —  Study  figures  on  pages  92,  93,  Civic  Biology. 

1.  What  is  the  source  of  the  water  used  in  the  leaf? 

2.  Where  does  the  carbon  dioxide  come  from?  Trace  it  back 
to  its  manufacture. 

3.  What  does  the  sun  have  to  do  with  the  work  of  a  leaf? 
Conclusion.  —  Write  a  paragraph  telling  how  starch  is  made 

in  a  leaf.      Use  the  terms  machinery,  raw  materials,  manufac- 
tured products. 

Prohletn  74:  To  show  that  a  £as  is  given  off  as  a  waste 
product  when gj^een  plants  make  starch. 

Materials.  —  Elodea,  glass  jar,  funnel,  test  tube. 

Method  and  Observations.  —  Place  some  i^M^a  under  a  funnel 
in  fresh  water.  Then  invert  a  test  tube  filled  with  water  over  the 
funnel.     See  that  the  tube  of  the  funnel  is  completely  filled  with 


PROBLEM   QUESTIONS  89 

water.  Place  the  jar  in  the  sunH<!;hl  for  a  day  or  two  and  collect 
any  escaping  gas  in  the  test  tube.  (Sec  figure  on  page  95,  Civic 
Biology.)  If  carbon  dioxide  is  occasionally  ])asscd  from  a  gener- 
ator through  the  water  in  the  jar,  the  evolution  of  the  gas  is 
increased.  Place  a  glowing  splinter  in  the  gas.  What  hajipens? 
What  does  thi^  indicate?  Set  up  the  apparatus  again  and  let  it 
stand  overnight.     Has  any  gas  been  formed  ? 

Note.  —  The  process  of  starch  formation  in  green  leaves  in  sunlight  is  callecl 
photosynthesis  {photo  —  light,  and  synthesis  —  a  building  up).  Cheniirally,  water 
(H2O)  and  carbon  dioxide  (CO2)  are  built  up  by  the  energy  of  the  sun  into  a  sub- 
stance which  ultimately  becomes  starch  (CeHioOs).  During  this  process  oxygen 
gas  is  given  off  as  a  by-product. 

Conclusion.  —  1.  If  work  is  done  by  the  plant,  then  how  does  it 
use  oxygen  ? 

2.  What  gas  would  a  green  plant  give  off  at  night?     Explain. 

3.  What  gas  would  be  given  off  in  the  sunlight? 

Problem  Questions 

1.  What  substances  are  given  off  by  green  leaves? 

2.  Trace  the  pathway  of  water  in  a  dicotyledonous  plant  from 
the  time  it  enters  to  the  time  it  leaves  the  plant. 

3.  What  does  a  plant  do  with  the  water  it  takes  in  ?  The  gases 
of  the  air  that  enter  the  leaves?  The  mineral  matter  that  passes 
in  through  the  roots  ? 

4.  If  dead  plants  are  burned  in  the  fall,  does  as  much  raw  food 
material  get  back  in  the  soil  as  if  the  dead  bodies  were  plowed 
under? 

5.  Why  are  green  plants  said  to  be  constructive  while  animals 
are  said  to  be  destructive  ? 

6.  Compare  a  leaf  to  a  factory.  Where  does  the  energy  to  run 
the  plant  come  from? 

7.  Why  should  the  leaves  of  plants  in  our  homes  })e  frequently 
dusted  and  washed? 

8.  Why  do  the  leaves  of  lettuce  or  cabbage  when  "  heailed  " 
turn  white? 

9.  What  are  some  adaptations  in  leaves  to  nn-eive  light? 
10.    Find  some  ways  in  which  leaves  aie  protected. 


90 


PLANTS   MAKE   FOOD 


11.   Fill  out,  with  the  help  of  your  teacher,  a  table  like  the 
following  as  a  summary  of  the  functions  of  leaves : 


Taken  in 

Given  out 

C  ond  1 1  io  n$  ui\cler 
vuhicK     yjroce*^ 
to-keS      -pltxce 

Fini$l\ed 
Prodxrct 

Respiration 

Transpir  otioiv 

PhotosyntKesis 

Prot  elninakin  0 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  VII.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chap.  IX.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  IX.     American  Book  Company. 

Bartlett,  Values  from  City  Garbage.     Engineering  Magazine,  May,  1914. 

Coulter,  Barnes,  and  Cowles,  A  Textbook  of  Botany,  Vol.  II.  American  Book 
Company. 

Dana,  Plants  and  Their  Children,  pp.  135-185.     American  Book  Company. 

Goodale,  Physiological  Botany,  pp.  337-353  and  409-424.  American  Book  Com- 
pany. 

Lubbock,  Flowers,  Fruits,  and  Leaves,  last  part.     The  Macmillan  Company. 

MacDougal,  Practical  Textbook  of  Plant  Physiology.  Longmans,  Green  and 
Company. 

Ward,  The  Oak.     D.  Appleton  and  Company. 


VIII.    PLANT  GROWTH   AND   NUTRITION  —  THE   CIR- 
CULATION AND  FINAL  USES  OF  FOOD  BY  PLANTS 

Problem.  —  How  green  plants  stor^e  and  use  tlie  food  tJiey 
make. 

(a)  What  are  the  organs  of  circulation  ? 

(b)  How  and  where  does  food  circulate  ? 

(c)  How  does  the  plant  assimilate  its  food  ? 

Laboratory  Suggestions 

Laboratory  exercise.  —  The  structure  (cross  section)  of  a  woody  stem. 
Demonstration.  —  To  show  that  food  passes  downward  in  the  bark. 
Demonstration.  —  To  show  the  condition  of  food  passing  through  the 
stem. 

Demonstration.  —  Plants  with  special  digestive  organs. 

To  THE  Teacher.  —  The  work  following  is  simply  intended  to  develop  the  con- 
cept that  the  stem  is  an  organ  of  circulation  ;  that  it  puts  the  upper  part  of  the 
plant,  the  food-making  organs,  in  connection  with  the  lower  part  of  the  plant,  the 
organs  which  absorb  raw  materials  for  food  making  and  which  act  as  a  storage  for 
manufactured  food. 

Problem  75 :  Groups  of  plants  told  hy  the  structure  of  their 
steins. 

NOTE.  —  Plants  which  produce  flowers  are  divided  into  two  great  groups  depend- 
ing on  whether  they  have  one  or  two  cotyledons  in  the  seed,  i.e.,  monocotyledons 
and  dicotyledons.  A  bean  is  an  example  of  the  latter,  a  corn  plant  of  tlic  former. 
Certain  marked  differences  in  the  leaves  or  stems  also  appear,  the  dicotyledon 
usually  has  veins  forming  a  network  while  those  of  the  monocotyledon  usually  run 
parallel  to  each  other.  A  third  difference  is  seen  in  the  stem.  In  the  dicotyledon 
growtli  takes  place  from  just  under  the  bark  and  we  have  annual  rings  of  growth 
which  tell  us  approximately  the  age  of  the  stem.  In  a  monocotyledon  (for  example 
a  cornstalk)  the  main  bulk  of  the  stalk  is  made  up  of  pith,  while  scattered  through 
the  pith  are  numerous  stringy,  tough  structures.  These  are  fihroiascular  bundles. 
The  outside  of  the  corn  stem  is  formed  of  large  numbers  of  these  bundles,  which, 
closely  packed  together,  form  an  outer  riiid.  Thus  the  woody  material  gives 
mechanical  support  to  an  otherwise  spongy  stem. 

91 


92      CIRCULATION  AND   USES  OF   FOOD   BY    PLANTS 


DiCotyledoa     Monocotyledon 


e  e 


Observations. — 
Compare  stems  of  a 
dicotyledon  (apple) 
and  a  monocotyledon 
(corn) ;  also,  leaves  of 
dicotyledons,  oak,  elm, 
or  chestnut  with  those 
of  monocotyledons, 
lily,  grass,  or  corn. 

Conclusion.  —  1. 
Make  table  comparing 
differences  of  (1)  stems, 
(2)  leaves,  (3)  seeds. 
Note  the  difference  in 
position  in  the  stem 
of  pith  and  bundles. 
(Use  lens.) 

2.  Where  is  the 
woody  part  in  a  dicoty- 
ledon? Where  in  a 
monocotyledon? 

Problem     76:     To 

study   the   structure 
of  a  woody  stein. 

Materials.  —  Small 
cross  sections  of  apple, 
horse  chestnut,  or  any 
other  woody  stem. 
Page   98,    Civic   Biol- 

ogy- 

Observations.  —  In  a  cross  section  of  apple  or  any  other  woody 
twig  note:  1.  The  central  soft  part,  the  pith.  2.  The  wood. 
3.  The  hark.  Can  you  find  radiating  lines,  medullary  rays,  in  the 
wood?     How  many  layers  of  bark  do  you  see? 


^f 


em 


c,  cotyledon  ;    e,   endosperm ;    h,  hypocotyl ;   p,  plu- 
mule ;  fh,  fibrovascular  bundles. 


Note.  —  Between  the  wood  and  the  bark  is  a  rapidly  growing  layer  called  the 
cambium. 


PROBLEM   77 


93 


Conclusion.  —  1.  Ju(lj2;c(l  from  the  texture,  what  iiiij!;lit  be  the 
use  to  the  plant  of  the  outer  layer  of  the  l)ai-k  ? 

2.  Judged  from  the  color,  what  might  l)e  the  use  of  the  middle 
layer  ?  * 

NOTE.  —  The  inner  layer  of  bark  is  known  as  the  hast.  It  consists  of  tuliclike 
cells  which  carry  food  from  the  leaves  toward  the  roots. 

3.  What  are  all  the  uses  of  the  bark? 

Drawing.  —  Make  a  cross  section  of  a  woody  stem,  labeling  all 
the  parts. 

Home  Work.  —  Take  two  potatoes  of  equal  weight.  Peel  one, 
leave  the  other  unpeeled.  Place  the  peeled  potato  (with  peelings) 
on  one  pan  of  a  balance,  the  unpeeled  potato  on  the  other.  Allow 
these  to  remain  on  the  balance  for  several  days.  What  changes 
do  you  note?  Remembering  that  the  potato  is  an  underground 
stem,  determine  another  function  of  the  bark.  (See  page  99, 
Civic  Biology.) 

Problem  77 :  To  prove  that 
liquids  rise  through  stems. 
(Review.) 

Materials.  —  Growing  pea  or 
bean  seedling,  red  ink. 

Method.  —  Place  the  roots 
of  a  growing  plant  in  a  weak 
solution  of  eosin  or  red  ink. 
Leave  a  few  hours  in  a  sunny 
place. 

Observations.  —  Notice  the 
stems  and  leaves  of  the  young 
plants,  particularly  the  veins  in 
the  leaves.  Copy  the  accom- 
panying figures  in  your  note- 
book and  color  them  to  show 
where  fluids  rise. 

Conclusion.  —  Through  what 
part  of  the  stem  and  leaves 
uo  liquids  rise? 


94      CIRCULATION   AND   USES   OF   FOOD   BY   PLANTS 

Problein  7S:  To  find  out  through  which  part  of  a  woody 
stem  food  passes  down. 

Materials.  —  Growing  willow  twigs,  nutrient  solution,  or  water. 
Upper  figure  page  100,  Civic  Biology. 

N.  B.  —  This  experiment  should  be  started  at  least  three  weeks  before  it  is  to  be 
used. 

Method.  —  Allow  willow  twigs  to  grow  in  water  until  they  have 
formed  roots,  then  girdle  them  by  removing  a  strip  of  bark 
about  half  an  inch  wide  and  about  an  inch  above  the  cut  end  of 
the  twig.     Replace  the  twigs  in  water. 

Observations.  —  After  several  days  notice  what  has  happened 
both  above  and  below  the  girdled  area. 

Conclusion.  —  1.  Through  which  part  of  the  stem  does  food 
get  to  the  roots?     How  do  you  know? 

2.  Write  a  paragraph  telling  how  water  rises  and  food  materials 
pass  through  a  woody  stem,  giving  reasons  from  this  and  other 
experiments. 

Drawing.  —  Illustrate  your  experiment  with  drawings  before 
and  after  girdling.  The  teacher  should  at  this  point  recall  the 
experiment  to  show  the  condition  of  the  food  in  the  stem  or  root 
when  it  passes  up  or  down  through  the  fibro vascular  bundles. 

Problem  79 :  How  plants  with  special  digestive  organs  get 
their  nitrogenous  food. 

Materials.  —  Specimens  of  pitcher  plant,  sundew,  Venus's-fly- 
trap,  and  charts  to  illustrate.     Figures  page  102,  Civic  Biology. 

Observations.  —  Look  carefully  within  the  pitcherlike  leaves  of 
the  pitcher  plant.  What  do  you  find  ?  With  the  aid  of  the  chart 
work  out  exactly  how  the  sundew  and  Venus's-flytrap  catch 
insects. 

Conclusion.  —  What  do  the  above  plants  do  with  the  dead 
insects  ? 

Problem  Questions 

1.  Of  what  use  to  a  plant  is  each  part  of  a  woody  stem? 

2.  In  what  condition  must  food  be  to  pass  through  a  stem? 
How  do  you  know? 


REFERENCE   BOOKS  95 

3.  In  what  condition  nuist  food  \)v  in  order  to  Ix*  sfonrf  in  the 
cells  of  a  plant?     Explain. 

4.  Mention  some  stems  in  which  food  is  stored.      From  where 
must  this  food  have  come? 

5.  What  is  the  cambium  layer  and  what  is  its  use  to  a  plant  ? 

6.  Look  up  a  reference  textbook  to  find   out   how   water  and 
food  pass  up  and  down  a  monocotyledonous  stem. 

7.  Read  a  textbook  to  find  out    how  a  dicotyledonous  stem 
grows.     How  a  monocotyledonous  stem  grows. 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  VIII.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chap.  VIII.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  VIII.     American  Book  Company. 

Andrews,  A  Practical  Course  in  Botany,  pp.  112-127.     American  Book  Company. 

Apgar,  Trees  of  the  Northern  United  States,  Chaps.  II,  V,  VI.  American  Book 
Company. 

Atkinson,  First  Studies  of  Plant  Life,  Chaps.  IV,  V,  VI,  VIII,  XXI.  Oinn  and 
Company. 

Coulter,  Plant  Life  and  Plant  Uses,  Chap.  V.     American  Book  Company. 

Coulter,  Barnes,  and  Cowles,  A  Textbook  of  Botany,  Vol.  I.  American  Book  Com- 
pany. 

Dana,  Plants  and  Their  Children,  pp.  99-129.     American  Book  Company. 

Duggar,  Plant  Physiology.     The  Macmillan  Company. 

Ganong,   The  Teaching  Botanist.     The  IMacmillan  Company. 

Goebel,  Organography  of  Plants,  Part  V.     Clarendon  Press. 

Goodale,  Physiological  Botany.     American  Book  Company. 

Gray,  Structural  Botany,  Chap.  V.     American  Book  Company. 

Hodge,  Nature  Study  and  Life,  Chaps.  IX,  X,  XL     Ginn  and  Company. 

Kerner-Oliver,  Natural  History  of  Plants.     Henry  Holt  and  Company. 

MacDougal,  The  Nature  and  Work  of  Plants.     The  Macmillan  Company. 

Mayne  and  Hatch,  High  School  Agriculture.     American  Book  Company. 

Strasburger,  Noll,  Scheuck,  and  Schimper,  A  Textbook  of  Botany.  The  Macmillan 
Company. 

Ward,  The  Oak.     D.  Appleton  and  Company. 

Yearbook,  U.  S.  Department  of  Agriculture,  1S94,  1895,  1898-1910. 


IX.   OUR    FORESTS,    THEIR    USES    AND    THE    NECES- 
SITY  FOR  THEIR   PROTECTION 

Problem.  — Man's  j^elations  to  forests. 

(a)    What  is  the  value  of  forests  to  jnan  ? 

(h)    What  can  man  do  to  prevent  forest  destruction  ? 

Laboratory  Suggestions 

Demonstration  of  some  uses  of  wood.  —  Optional  exercise  on  structure 
of  wood.  Method  of  cutting  determined  by  examination.  Home  work 
on  study  of  furniture,  trim,  etc. 

Visit  to  Museum  to  study  some  economic  uses  of  wood. 

Visit  to  Museum  or  field  trip  to  learn  some  common  trees. 

To  THE  Teacher.  —  The  practical  value  of  work  on  forestry  is  unquestioned. 
Every  pupil  of  high  school  age  should  have  not  only  some  knowledge  of  our  forests 
and  their  uses,  but  also  a  little  first-hand  experience  in  recognition  of  some  common 
trees  :  their  habitat  and  their  use.  The  methods  of  cutting  lumber  and  trim  also 
gives  a  practical  side  which  is  of  interest  to  pupils. 

Prohle^n  80:  To  determine  how  lumber  is  cut  and  how  to 
recognize  the  cut  in  trim. 

Materials.  —  Diagrams,  school  furniture.  Hough's  sections  of 
woods. 

Method.  —  Examine  the  sections  shown  you.  Compare  with 
lower  figure,  page  111,  Civic  Biology. 

Note.  —  Most  lumber  is  cut  tangentially.  Hence  the  yearly  rings  take  a  more 
or  less  irregular  course.  The  grain  of  wood  is  caused  by  the  fibers  not  taking 
straight  lines  in  their  course  in  the  tree  trunk.  In  many  cases  the  fibers  of  the 
wood  take  a  spiral  course  up  the  trunk,  or  they  may  wave  outward  to  form  little 
projections.  Boards  cut  out  of  such  a  piece  of  wood  will  show  the  effect  seen  in 
many  of  the  school  desks,  where  the  annual  rings  appear  to  form  small  elliptical 
markings. 

Study  the  top  of  your  desk,  the  wainscoting,  the  floor,  and  any 
other  wood  at  hand  to  determine  the  kind  of  cutting.     Study 

96 


PROBLEM   82 


97 


the  figures  and  compare  with  the  specimens  of  wood  just  m^ii'd. 
Can  you  observe  any  differences  in  color  of  the  wood  ? 

Conclusion.  —  1.  What  is  tiie  common  method  of  cuttinj^  wood 
for  trim?     Why? 

2.  Does  most  dried  wood  show  any  difference  between  heart 
and  sap  wood  ?     Wliat  is  this  difference  ? 

Problem  81 :  To  determine  some  uses  of  steins. 

Method.  —  See  Chap.  X,  page  133,  Hunter's  Essentials  oj 
Biology,  or  Chap.  IX,  page  105,  Hunter's  Civic  Biology.  After 
reading  carefully  fill  in  the  following  table : 


SuV»stciTtce- 

Fpoitv  v/Kat  plant? 

Trom  v/hat  locality? 

Cork 

FoodL 

Txx^\ 

Hemp 

Lcit  ex  for  Rubber 

LirvGiv 

LT-iin.t»  er 

Q,\^xrvTTxe 

ReSitx 

Swgrctl- 

^C¥  rVlVXTV 

>*I^x>ivpeT\tiT\e.|j 

V/ood  T*wlp         1 

Conclusion.  —  Write  a  paragraph  sununing  up  the  uses  of  stems 
to  man. 


Problem  82 :  To  determine  tJie  value  of  certain  ivoods. 

Method.  —  Find  out  as  many  woods  as  you  can  tliat  are  of 
value  because  of  properties  listed  in  the  following  table  and  record 
in  proper  colunm.  See  Chap.  X,  Hunter's  Essentials  of  Biology, 
or  Chap.  IX,  Hunter's  Civic  Biology.  After  reading  your  text, 
or  taking  a  trip  to  a  commercial  museum,  till  out  the  table 
on  page  98. 

HUNTER   LAB.   PROS. — 7 


98 


OUR  FORESTS 


P«pei»  r^cik.iTv.g 

I>  XA.  T»al>  ill  ty- 
ond  ^trei\g"tK 

So/tiwesg 

of  Gx^aliv 

Conclusion.  —  1.  Which  woods  are  useful  for  skeletons  of  houses  ? 

2.  Which  are  useful  for  trim? 

3.  Which  are  useful  for  paper  making? 

4.  In  general,  which  are  more  used,  soft  or  hard  woods? 

Problem  S3 :  Museum  trip  for  study  of  woods. 

Materials.  —  Collection    of   commercial   woods,    or   trip   to   a 
museum.^ 

Method  and  Observations.  —  Examine  specimens  of  the  most 


important  commercial  woods. 

white  pine  spruce 

black  cherry  tulip 

hemlock  fir 

hickory  walnut 


Note  such  woods  as 

sugar  maple 
poplar 
black  oak 
cherry 


white  oak 
basswood 
chestnut 
white  birch 


Describe  any  six  of  the  above,  telling : 

(a)  The  region  where  the  trees  grow. 

(6)  The  shape  of  the  leaves. 

(c)  The  color  of  heart  and  sap  woods. 

{d)  Comparative  weight  of  the  wood. 

(e)  Rapid  or  slow  growth. 

(/)  Economic  value. 

Examine  a  specimen  of  a  section  of  any  big  tree,  such  as  a 
California  big  tree.  Notice  the  so-called  annual  rings  in  the 
wood.     About  how  old  was  this  tree  when  it  was  cut? 


1  A  study  such  as  here  outlined  may  be  made  at  any  well-equipped  city  museum. 
Work  of  this  nature  may  also  be  done  in  school  by  means  of  loan  collections. 


PROBLEM   84 


99 


If  you  go  to  school 
in  New  York  city  use 
this  diagram  for  your 
notebook. 

Conclusion.  —  If  a 
trip  is  taken,  write 
out  carefully  a  report 
of  the  observations 
made. 

Problem    84 :     To 

identify  coimnon 
trees  hy  the  use  of  a 
hey. 

Materials.  —  Vari- 
ous specimens  of  wood 
with  leaves  on  twigs ; 
pictures  of  trees,  flow- 
ers, and  fruits ;  ruler. 

Method  and  Obser- 
vations. —  Using  the 
material  and  the  Key 
on  the  following  pages 
under  the  supervision 
of  your  teacher,  make 
careful  observations 
of  leaves  given  you. 
Note  and  measure 
size  of  leaf,  structure, 
shape,  etc.  Refer  to  the  Key  which  follows.  Doterniino  whether 
the  specimen  which  you  have  belongs  under  A  or  B.  If  it  belongs 
under  A,  for  example,  then  place  it  under  1  oi'  II.  Having  done 
this,  determine  wliether  it  is  (i,  />,  or  c,  then  1,  2,  or  3,  etc., 
until  you  hnally  determine  the  sj)e('imen  of  leaf,  and  by  it,  the 
name  of  the  kind  of  tree  to  which  it  belongs. 

Conclusion.  —  What  are  the  names  of  the  various  trees  from 
which  you  have  made  observations? 


A  Diagram  of  the  Hall  coxtaimng  the  Jks.sli' 
Collection  of  Woods,  Ameuica.v  Museu.m  of 
Natural  History,  New  York. 


100  OUR  FORESTS 

KEY  TO  SOME  OF  THE  COMMON  TREES  OF  THE 
NORTHEASTERN  UNITED   STATES 

The  following  Key  was  prepared  by  George  T.  Hastings  of  the 
Department  of  Biology  of  the  DeWitt  Clinton  High  School. 

This  Key  does  not  include  the  common  cultivated  fruit  trees,  or 
any  but  the  commonest  of  cultivated  shade  or  ornamental  trees. 

A.  Leaves,   needle-shaped,   or  very  small,   scalelike.      Evergreen  trees, 

except  No.  9. 

Conifers  or  Soft  Woods 

I.  Leaves  needle-shaped. 

a.  Leaves  over  \\  inches  long,  in  bundles  of  2,  3,  or  5. 

1.  Leaves  5  in  a  cluster.  1.   White  Fine. 

2.  Leaves  3  in  a  cluster.  2.  Fitch  Fine. 

3.  Leaves  2  in  a  cluster. 

*Leaves  1^  to  3  inches  long.  3.  Scotch  Fine. 

**Leaves  3  to  5  inches  long.  4.  Austrian  Fine. 

b.  Leaves  about  1  inch  long,  many  in  a  cluster  on  tiny  knoblike 

branches.  5.  Larch  or  Tamarack. 

c.  Leaves  less  than  1|  inches  long,  singly  on  the  twigs. 

1.  Leaves  flattened,  growing  horizontally  on  the  twigs. 

*About  I  inch  long.  6.  Hemlock. 

**  f  to  1  inch  long.  7.  Balsam. 

2.  Leaves  4  angled,  growing  on  all  sides  of  the  twigs. 

*Leaves  dark  green,  cones  4  inches  or  more  long. 

8.  Norway  Spruce. 
**Leaves  bluish  green,  cones  1§  to  2  inches  long. 

9.   White  Spruce. 
II.  Leaves  scalelike,  very  small. 

a.  Leaves  rounded,   overlapping,   flattened  on  the   twigs,   which 

appear  as  if  ironed  out  flat.     Fruit  a  cone  about  |  inch  long. 

10.    White  Cedar  or  Arbor  Vitoe. 

b.  Leaves   sharp-pointed,  on   all  sides  of  the  rounded  or  square 

twigs.     Fruit  a  small  blue  berry.        11.  Red  Cedar  or  Juniper. 

B.  Leaves  not  needle-shaped  or  scalelike. 

Broad-leaved  or  Hardwood  Trees 

I.  Leaves  in  pairs,  opposite  on  the  branches. 

a.  Leaves  simple,  palmately  veined,  notched  or  lobed. 

1.  The  depressions  between  the  3  to  5  lobes  narrow,  acute, 
twigs  red. 


KEY   TO   SOME   OF   THE   COMMON   TP.EKS        101 

♦Leaves  notched  less  than  halfway  to  the  niidrih. 

11'.    Iii<l  Maple. 
**Leaves  divided  more  than  halfway.        l.i.  Silnr  Maple. 
2.  The   depressions    between    the    lobes    bro.-id    and    roiindfd, 
twigs  brown  or  greenish. 

•^Twigs  slender.  11.   Suyar  Maple. 

^Twigs  stout,  petioles  when  broken  exude  acrid  milky  sap, 
which  coagulates.  15.  Norway  Maple. 

b.  Leaves  simple,  entire,  pinnately  veined. 

l(i.   Flowering  Dogwood. 

c.  Leaves  compound. 

1.  Palmately  compound.  17.   Horse-chestnut. 

2.  Pinnately  compound. 

*Leaflets  3  to  5,  coarsely  dentate.  IS.   Box  Elder. 

**Leaflets  5  to  9,  finely  serrate,  each  with  a  short  stalk. 

19.  ir/a/e  Ash. 
***Leaflets  7  to  11,  finely  serrate,  without  stalks. 

20.  Black  Ash. 
IL  Leaves  large,  entire,  growing  3  at  a  joint  on  the  twigs. 

21.  Catalpa. 
III.  Leaves  alternate  on  the  twigs,  one  at  a  joint. 
a.  Leaves  simple.     (For  b  see  page  103.) 

1.  Leaves  palmately  veined. 

*Leaves  star-shaped,  with  5  to  7  sharp  lobes. 

22.  Sweet  Gum. 
**Leaves  broadly  oval,  toothed  or  irregularly  lobed. 

23.  Sycamore. 

2.  Leaves  pinnately  veined. 

*Not  deeply  cut  or  lobed. 

fLeaves  narrow,  lanceolate. 

'Twigs  slender,  not  greatly  drooping,  leaves  smooth 
and  green  both  sides. 

24.   Fragile  or  Crack  Willow. 
'  'Twigs  slender,  not  greatly  drooping,  leaves  with 
small  hairs  and  pale  on  both  sides. 

2').    White  Willow. 
•  •  'Twigs  very  slender,  drooping,  leaves  smooth. 

2r).    Weeping  Willow. 
t fLeaves  broader,  oval  or  ovate. 

'Leaves  dentate,  smooth.  27.   Buck. 

'  'Leaves  serrate. 

'Bark   on    twigs   and    branches    smooth,    shining, 
black,  bitter  to  the  taste. 

28.   Black  Cherry. 


102  OUR  FORESTS 

"Bark  not  as  in  '. 

iLeaves  usually  4  inches  or  more  long. 
iLarge  sharp  teeth  on  edges. 

29.   Chestnut. 
!  ILarge  rounded  teeth  on  edges. 

30.  Chestnut  or  Rock  Oak. 
:  :Leaves  less  than  4  inches  long. 

iLeaves  smooth,  in  more  than  2  rows  on  the 

stem,  bark  peeling  in  thin  sheets. 
X.  Twigs  brown,  bark  with  wintergreen  flavor, 
bark  dark  brown  or  black. 

31.   Black  Birch. 
y.  Twigs  gray  or  yellowish,  trunk  silvery  or 
grayish. 

32.    Yellow  Birch, 
z.  Twigs  brownish,  bark  chalky  white. 

33.   White  Birch. 

!  ILeaves  rough,  in  2  rows  on  the  twigs. 

X.  Leaves  very  rough  above,  buds  and  twigs 

hairy,     grayish,     mucilaginous     when 

chewed.  34.  Slippery  Elm. 

y.  Leaves  slightly   rough    above,  buds    and 

twigs  smooth   or  nearly   so,  brown  or 

reddish,  not  mucilaginous. 

35.   American  Elm. 
ttfLeaves  as  broad  as  long,  or  broader. 
"Leaves  sharp-pointed. 

'Petioles  (leafstalks)    flattened  at  right   angles  to 
the  blade. 
:Tree  tall,  slender,  branches  all  ascending. 

3G.  Lomhardy  Poplar. 
:  :Tree  broader,  leaves  green. 

37.   Carolina  Poplar. 
: :  :Tree  broader,  leaves  white  below. 

38.   White  Poplar. 
"Petioles  rounded. 

39.   Basswood. 
'  "Leaves  rounded  at  tip  often  with  a  lobe  on  one  or 
both  sides.  40.  Sassafras. 

' '  "Leaves  square,  or  notched  at  tip  and  sides. 

41.    Tulip  Tree  or  Tulip  Poplar. 
**Leaves  deeply  cut  or  lobed. 

fLobes  rounded.  42.   White  Oak. 

tfLobes  sharp-pointed. 


PROBLEM   Qin^.STI()NS  103 

•Lobes  cut  less  than  halfway  to  midrib,  smootli,  acorn 
large  (1  inch  long)  with  shallow  cup. 

43.   Red  Oak. 

'  "Lobes  cut  more  than  halfway,  acorns  small  {\  inch  or 

less),  cup  covering  at  least  \  of  acorn. 

'Leaves   smooth   both   sides,   scales  of  cup   pressed 

down  at  tip.  44.  Scarlet  Oak. 

"Leaves  hairy  below,  at  least  in   the  angles  of  the 

veins,  scales  of  cup  spreading  at  tip. 

45.  Black  or  Yellow-barked  Oak. 
b.   Leaves  compound. 

1.  Trunks  or  branches  thorny,  leaflets  rounded  at  the  tip. 

*Thorns  large,  often  3  parted.  46.  Honey  Locust. 

**Thorns  small,  in  pairs  at  the  base  of  leaves,  or  sides  of 

leaf  scars.  47.  Common  Locust. 

2.  No  thorns,  leaflets  pointed  at  tip. 

*Twig  very  stout,  ^  inch  or  more  in  diameter.     Leaflets 
11  or  more. 
fTwigs  smooth.  48.  Ailanthus. 

tfTwigs  very  hairy.  •    49.  Staghorji  Sumach. 

**Twigs  more  slender,  not  over  j  inch  thick  at  tip. 
fLeaflets  11  or  more. 

•Twigs  smooth,  nut  round.  50.  Black  Walnut. 

'  "Twigs  downy,  nut  oval.  51.  Butternut. 

t  fLeaflets  9  or  less. 

•Bark  of  tree  furrowed,  not  in  long  flat  plates. 

52.    Pignut. 
'  'Bark  of  tree  in  long  flat  plates  loose  at  lower  end. 

53.  Shagbark   Hickory. 

Problem   Questions 

1.  What  are  the  direct  uses  of  stems  to  man? 

2.  What  are  the  direct  uses  of  stems  to  plants? 

3.  How  are  forests  of  value  to  man? 

4.  Name  three  enemies  of  the  forests. 

5.  Name  three  ways  of  conserving  our  forests. 

6.  How  do  the  forests  of  New  York  indirectly  influence  the 
commercial  importance  of  New  York  city? 

7.  What  special  tree  products  give  factories  employment  in 
your  home  city? 

8.  Of  what  value  are  trees  in  a  city  jiark? 

9.  Look  in  your  Civic  Biology  and  find  ten  ways  in  wliich  troos 
are  of  value  in  a  city. 


104  OUR  FORESTS 


Reference  Books 

Hunter,  Civic  Biology,  Chap.  IX.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chap.  VIII.     American  Book  Company. 

Huiiter,  Essentials  of  Biology,  Chap.  X.     American  Book  Company. 

Andrews,  Botany  All  the  Year  Round,  Chaps.  VI,  VII.     American  Book  Company. 

Apgar,  Ornamental  Shrubs.     American  Book  Company. 

Apgar,  Trees  of  the  Northern  United  States,  Chaps.  II,  V,  VI.  American  Book 
Company. 

Atkinson,  First  Studies  of  Plant  Life,  Chaps.  IV,  V,  VI,  VIII,  XXI.  Ginn  and 
Company. 

Bailey,  Trees  in  Winter,  How  they  Look.  Teachers^  Leaflets,  Nature  Study,  No.  12, 
Cornell  University,  January,   1899. 

Bergen  and  Caldwell,  Practical  Botany,  Chap.  XXII.     Ginn  and  Company. 

Blakeslee  and  Jarvis,   Trees  in  Winter.     The  Macmillan  Company. 

Burba,  Tree  Surgery.     Pearson's  Magazine,  April,  1910. 

Burroughs,  The  True  Test  of  Nature  Literature.  Country  Life  in  America,  May, 
1904. 

Camphor  Tree.     Botanical  Circular  12,  U.  S.  Department  of  Agriculture. 

Coal  as  a  Commercial  Factor.     Metropolitan  Magazine,  March,  1909. 

Coles-Finch,  Water,  Its  Origin  and  Use.     D.  Van  Nostrand  and  Company. 

Commercial  Tree  Studies.  U.  S.  Department  of  Agriculture,  Forestry  Service, 
Bulletins  13,  22,  31,  33,  37,  38,  53,  58,  and  64. 

Coulter,  Plant  Life  and  Plant  Uses,  Chap.  V.     American  Book  Company. 

Coulter,  Barnes,  and  Cowles,  A  Textbook  of  Botany,  Part  I  and  Vol.  II.  American 
Book  Company. 

Dana,  Plants  and  Their  Children,  pp.  99-129.     American  Book  Company. 

Duggar,  Plant  Physiology.     The  Macmillan  Company. 

Fernow,  A  Brief  History  of  Forestry  in  Europe.     University  of  Toronto. 

Fernow,  Care  of  Trees  in  Street,  Lawn,  and  Park.     Henry  Holt  and  Company. 

Fernow,  History  of  Forestry.     Forestry  Quarterly,  Cambridge,  Mass.,   1910. 

Forest  Fires  in  the  Adirondacks.  Forestry  Circular  26,  U.  S.  Department  of  Agri- 
culture. 

Forestry  in  Public  Schools.     Forestry  Circular  130,  U.  S.  Department  of  Agriculture. 

Ganong,  The  Teaching  Botanist.     The  Macmillan  Company. 

Goebel,  Organography  of  Plants,  Part  V.     Clarendon  Press. 

Goff  and  Mayne,  First  Principles  of  Agriculture.     American  Book  Company. 

Goodale,  Physiological  Botany.     American  Book  Company. 

Graves,  The  Advance  of  Forestry  in  the  United  States.  Review  of  Reviews,  April, 
1910. 

Gray,  Structural  Botany,  Chap.  V.     American  Book  Company. 

Hemp  Industry  in  the  United  States.  Yearbook,  1901,  U.  S.  Department  of  Agri- 
culture. 

Hodge,  Nature  Study  and  Life,  Chaps.  IX,  X,  XI.     Ginn  and  Compan5^ 

Hough,  Handbook  of  the  Trees  of  the  Northern  States  and  Canada.     Hough,  Lowville. 

Hough,  The  Slaughter  of  the  Trees.     Everybody's  Magazine,  May,  1908. 

Jackson,  Forestry  in  Nature  Study.  Farmers'  Bulletin  468,  U.  S.  Department  of 
Agriculture. 

Keeler,  Our  Northern  Shrubs  and  How  to  Identify  Them.     Charles  Scribuer's  Sons. 


REFERENCE   BOOKS  1U5 

Kellogg,  Lumber  and  lis  Uses.     Radford  Arohitcntural  rornpany. 

Kerner-Oliver,  Natural  History  of  Plants.     Henry  Holt  and  Company. 

MacDougal,  The  Nature  and  Work  of  Plants.     The  Maeniillan  C:oinpany. 

Maple  Sugar  and  Syrup.     Farmers'  Bulletin  232,  U.  S.  Department  of  Agriculture. 

Mayne  and  Hatch,  High  School  Agriculture.     American  Book  Company. 

Moon  and  Brown,  Elements  of  Forestry.     ,J.  Wylie  and  Sons. 

Murrill,  Shade  Trees.  Bulletin  205,  Cornell  University  Agricultural  Experiment 
Station. 

Newell,  The  Reclamation  of  the  West,  p.  827.  Annual  Report  Smithsonian  Insti- 
tution, 1904. 

Osterhout,  Experiments  with  Plants,  Chap.  V.     The  Macmillan  Company. 

Pinchot,  The  Forest  Service.     U.  S.  Department  of  Agriculture,  Circular  30,  li)()0. 

Pinchot,  Primer  of  Forestry.  Farmers'  Bulletin  173,  U.  S.  Department  of  Agri- 
culture. 

Rogers,  The  Tree  Book.     Doubleday,  Page  and  Company. 

Rogers,  Trees  Every  Child  Should  TCnow.     Doubleday,  Page  and  Company. 

Roosevelt  and  others.  Forests  and  Timber  Supply.  Forestry  Circular  25,  U.  S. 
Department  of  Agriculture. 

Roosevelt  and  others.  Forest  Preservation  and  National  Prosperity.  Forestry  Cir- 
cular 25,  U.  S.  Department  of  Agriculture. 

Stevens,  Fungi  Which  Cause  Plant  Disease.     The  Macmillan  Company. 

Strasburger,  Noll,  Schenck,  and  Schimper,  A  Textbook  of  Botany.  The  Macmillan 
Company. 

Taylor,  Street  Trees,  Care  and  Preservation.  Cornell  University,  Agricultural 
Bulletin  256,  June,  1908. 

Treadwell,  A  Primer  of  Conservatism.  Circular  157,  Forest  Service,  U.  S.  Depart- 
ment of  Agriculture. 

Waning  Hardwood  Supply  of  the  Appalachian  Forests.  Forestry  Circular  1 IG, 
U.  S.  Department  of  Agriculture. 

Ward,  The  Oak.     D.  Appleton  and  Company. 

Ward,  Timber  and  Some  of  its  Diseases.     The  Macmillan  Company. 

Weed,  Our  Trees  and  How  to  Know  Them.     J.  B.  Lippincott  Company. 

Whipple  and  Wilson,  The  Part  Played  by  the  Forests  in  Everyday  Life.  Suburban 
Life,  April,  1908. 

Winkerwerdcr,  Forestry  in  the  Public  Schools.  Circular  130,  Forest  Service,  U.  S. 
Department  of  Agriculture,  1007. 

Wood  Distillation.     Forestry  Circular  111,  U.  S.  Department  of  Agriculture. 

Wyman,  Leaves  and  Acorns  of  our  Common  Oaks.  Teachers'  Leaflet,  Nature  Study, 
No.  8,  Cornell  University,  September,   1897. 

Yearbook,  U.  S.  Department  of  Agriculture,  Division  of  Forestry,  Bulletins  7,  10, 
13,  16,  17,  18,  20,  26,  27. 

Yearbook,  U.  S.  Department  of  Agriculture.  1894,  1895,  1898-1910. 


X.   THE   ECONOMIC   RELATION   OF   GREEN   PLANTS 

TO   MAN 

Problems.  —  How  ^reen  plants  are  useful  to  man. 

{a)  As  food. 

{h)  For  clothing. 

(c)    Other  uses. 

How  green  plants  are  harinful  to  man. 

Suggested  Laboratory  Work 

If  a  commercial  museum  is  available,  a  trip  should  be  planned  to 
work  over  the  topics  in  this  chapter.  The  school  collection  may  well 
include  most  of  the  examples  mentioned,  both  of  useful  and  harmful 
plants. 

A  study  of  weeds  and  poisonous  plants  should  be  taken  up  in 
actual  laboratory  work,  by  collection  and  identification,  or  by  demon- 
stration. 

To  THE  Teacher.  —  This  chapter,  which  is  intended  to  sum  up  the  preceding 
chapters  from  the  practical  aspect,  may  be  made  largely  in  the  nature  of  reading 
and  reports.  It  is  wise  when  teaching  a  course  in  biology  (or  any  other  subject) 
to  vary  the  work  as  much  as  possible,  both  to  maintain  interest  and  to  prevent 
stagnation  of  thought  on  the  part  of  the  pupil. 

Problem  85 :  To  cleter^7^ine  the  economic  importance  of  some 
green  plants. 

Materials.  —  Toothaker's  Commercial  Raw  Materials  is  an 
invaluable  reference  book  for  this  exercise.  This  might  well  be 
planned  for  a  field  and  museum  trip  to  some  commercial  museum, 
or  the  school  museum  may  be  used.  Also  visit  the  public  or  pri- 
vate markets  in  your  locality  and  Ust  all  the  food  plants  or  their 
products  used  for  food. 

Method.  —  Fill  out  a  table  like  the  following. 

Conclusion.  —  In  what  ways  are  green  plants  useful  to  man? 

106 


PROBLEM   80 


lu: 


Frvi  its 

Native 

Ciiltivaled 

\  isr.s  to 
M  ct  1  \ 

Interrtt 

Garden  Fruits 

Beccrvs 

CucvtrT\bp>i'.s- 

Pert  s 

P»,«i-»\pkii\s 

etc. 

• 

Orchard  Fruits 

A-pples 

Apricots 

C  K  e  i^r  i  e  s 

■p  e.  a  c  Vv  e.  ,s 

• 

Pe.ciT'* 

1*1  x;iro..s 

Q  «  1  r»  c  o  s 

etc. 

Gt  ct  i.i\  S 

Bcji'ley 

C  or^xv 

OcrtS 

Rice 

Rjy^e 

^^^lvecxt 

etc. 

Miscellaneous 

Barvcirvtxs 

Coco  Cf 

CoCon.vct 

Cofi 

e  e. 

Cot^ 

t  or\ 

Pepper^ 

etc. 

Problem  86:  To  learn  to  know  some  green  plants  Jiariiifjil  to 
man. 

Materials.  —  Copies  of  Chestnut's  Thirty  Poisonous  Plants  of 
the  U.  S.,  Farmers'  Bulletin  86,  and  Dewey's  Two  Hundred  Weeds, 
How  to  Know  Them  and  How  to  Kill  Them,  Farmers'  Bulletin  17. 
A  few  of  the  common  plants  which  are  weeds  in  your  locality. 
(Poison  ivy  can  be  studied  if  placed  in  air-tight  jars.) 

Method  and  Observations.  —  Using  Farmers'  Bulletin  8(),  iden- 
tify and  give  the  characters  by  which  you  would  know  the  follow- 
ing :  pokeweed,  corn  cockle,  black  cherry,  loco  weed  (very  harmful 
in  the  West),  snow-on-the-mountain,  poison  ivy,  poison  oak, 
poison  sumac,  water  hemlock,  poison  hemlock,  poison  weed,  black 
nightshade.  Using  Farmers'  Bulletin  17,  identify  and  classify 
ten  of  the  most  common  weeds  of  eastern  United  States. 

Conclusion.  —  1.  Write  a  paragraph  on  some  one  poisonous 
plant  and  the  best  means  of  eradicating  it  from  your  vicinity. 


108       RELATION   OF   GREEN    PLANTS   TO   MAN 

2.   Make  a  table  modeled  after  the  following.     In  it  place  any 
ten  plants  in  which  you  are  interested.     Fill  out  completely. 


^rV'eecl  ;S 

H  cibi  t  cc't 

E  5t  i  iKvcited. 

\A/hat  Keirnrt 

DctT\d.e  1  i  o  rv 

Catvcidct  Thistle 

Cockle  Tt3xi  r» 

>i:  ilk;  vvreed. 

Ox  ejy  e  D  «  i  Sjy 

F>  X  rf  %^y  e  e.  d. 

lE*xjc^S'i  cr  TV  e 

R  cc  g  -^jsr  eecl 

W^ild.  Ccn-x»o"t 

^ysTilcl  l^ettxice 

•  tc. 

Problem  Questions 

1.  What  effect  ought  plant  products  in  a  given  locality  to  have 
on  the  prices  of  animal  products  having  the  same  food  value? 
Is  this  true,  in  your  opinion  ?  Get  your  teacher  to  help  you  inter- 
pret this  question. 

2.  Name  ten  food  plants  grown  in  your  locality. 

3.  Name  ten  food  plants  that  must  be  imported  for  our  use. 

4.  Using  the  school  or  other  museum,  make  a  report  on  three 
different  fiber  plants,  giving  their  habitat,  method  of  manufacture 
from  raw  materials,  and  their  ultimate  uses  by  man. 

5.  Name  five  plants  used  for  medicine. 

6.  Discuss  the  value  of  some  one  plant  just  mentioned  as  a 
specific  remedy  against  some  particular  disease. 

7.  Show  three  ways  in  which  weeds  may  do  harm  to  man. 


Reference  Books 

Hunter,  Civic  Biology,  Chap.  X.     American  Book  Company. 
Hunter,  Elements  of  Biology,  Chap.  V.     American  Book  Company. 
Hunter,  Essentials  of  Biology,  Chap.  V.     American  Book  Company. 
Bailey,  Cyclopedia  of  American  Agriculture.     The  Macmillan  Company. 
Bailey,  The  Evolution  of  our  Native  Fruits.     The  Macmillan  Company. 


REFERENCE  BOOKS  109 

Bcrffen  and  Caldwell,  Practical  Botany.     Ginn  and  Company. 

Beif^en  and  Davis,  Principles  of  Botany.     Ginn  and  Company. 

Coulter,  Plant  Life  and  Plant  Uses.     American  Book  Company. 

Coulter,  Barnes,  and  Cowles,  A  Textbook  of  Botany,     .\moripan  Book  Company. 

Dunn,  Remedies  for  the  Beef  Famine.     Literary  Digest,  p.  773,  April  4,  1914. 

Gannett,  Garrison,  and  Houston,  Commercial  Geography,  Chtip.  IX.  American 
Book  Company. 

Georgia,  A  Manual  of  Weeds.     The  Macmillan  Company. 

Huntington,  Poisonous   Vagrant  Weeds.     House  and  Garden,  September,   1909. 

Kramer,  Applied  and  Economic  Botany.     B.  G.  Smith. 

Needham,  Natural  History  of  the  Farm.     Corastock  Pul)lishing  Company. 

Sargent,  Plants  and  Their  Uses.     Henry  Holt  and  Company. 

Sharpe,  A  Laboratory  Manual  in  Biology.     American  Book  Company. 

Toothaker,  Commercial  Raw  Materials.     Ginn  and  Company. 

U.  S.  Dept.  of  Agriculture,  Farmers'  Bulletin  86,  Thirty  Poisonous  Plants  of  the 
United  States,  V.  K.  Chestnut.  Bulletin  17,  Two  Hundred  Weeds,  How  to 
Know  Them  and  How  to  Kill  Them,  L.  H.  Dewey.  Bulletin  295,  Potatoes  and 
Other  Root  Crops  as  Food.     Bulletin  132,  Nuts  and  Their  Use  as  Food. 


XL   PLANTS  WITHOUT  CHLOROPHYLL  IN  THEIR 

RELATION   TO   MAN 

Problems,  —  {a)  How  molds  and  other  saprophytic  fungi  do 
hajnn  to  man. 

(b)  What  yeasts  do  for  manlcind. 

(c)  A  study  ofhacteida  with  reference  to 

(i)   Conditions  favorable  and  unfavorable  to  growth. 
{2)   Their  relations  to  manlcind. 

{3)  Some  methods  of  fighting  harmful  bacteria  and  dis- 
eases caused  by  them. 

Laboratory  Suggestions 

Field  work.  —  Presence  of  bracket  fungi  and  chestnut  canker. 

Home  experiment.  —  Conditions  favorable  to  growth  of  mold. 

Laboratory  demonstration.  —  Growth  of  mold,  structure,  drawing. 

Home  experiment  or  laboratory  demonstration.  —  Conditions  unfavor- 
able for  growth  of  molds. 

Demonstration.  —  Process  of  fermentation. 

Microscopic  demonstration.  —  Growing  yeast  cells.     Drawing, 

Home  experiment.  —  Conditions  favorable  for  growth  of  yeast. 

Home  experiment.  —  Conditions  favorable  for  growth  of  yeast  in  bread. 

Demonstration  and  experiment.  —  Where  bacteria  may  be  found. 

Demonstration.  —  Methods  of  growth  of  bacteria,  pure  cultures,  and 
colonies  shown. 

Demonstration.  —  Foods  preferred  by  bacteria. 

Demonstration.  —  Conditions  favorable  for  growth  of  bacteria. 

Demonstration.  —  Conditions  unfavorable  for  growth  of  bacteria. 

Demonstration  by  charts,  diagrams,  etc.  —  The  relation  of  bacteria  to 
disease  in  a  large  city. 

To  THE  Teacher.  —  In  these  days  when  the  application  of  biology  to  human 
welfare  is  so  often  made  the  chief  aim  of  a  course  in  biology,  it  is  refreshing  to  know 
that  there  are  teachers  left  who  beheve  in  logic  and  in  the  building  of  a  super- 
structure before  proceeding  to  work  upon  the  top  of  the  building.  In  point  of 
interest  and  of  instructive  value,  the  exercises  which  follow  are  vital ;  as  experi- 
ments, however,  they  are  not  always  absolutely  to  be  relied  upon.  The  extreme 
delicacy  with  which  some  of  the  factors  work,  the  fact  that  we  are  dealing  with 
microorganisms  which  cannot  be  handled  except  in  bulk,  the  fact  that  most  school 
laboratories  have  neither  equipment  nor  means  to  obtain  some  of  the  necessary 
materials,  make  absolutely  accurate  experiments  sometimes  out  of  the  question. 

110 


PROBLEM   S7  111 

The  method  of  science  can,  however,  be  used  and  all  reasonable  r;ire  and  acm- 
rary  1)0  given  in  the  perforinauee  of  any  experiments  which  follow. 

The  informational  content  is  certainly  of  the  widest  possible  importance.  An 
entire  course  could  well  be  devoted  to  the  numerous  experimental  questions  which 
present  themselves.  It  is  unwise,  however,  to  give  more  than  a  month  to  six 
weeks'  time  to  the  chapter  because  of  the  need  for  balance  in  the  course. 

Materials  for  the  study  of  bacteria  (nutrient  agar  or  gelatine)  may  be  obtained 
from  any  good  chemist,  from  manufacturing  chemists,  and  from  the  local  board  of 
health.  Directions  for  making  culture  media  follow  in  this  chapter,  but  the 
work  need  not  be  given  up  because  of  lack  of  proper  apparatus  or  laboratory  facil- 
ities. 

JProblem  S7 :  To  determine  the  relation  of  fungi  to  the  de- 
struction of  certain  trees. 

NOTE.  —  Suggestions  for  field  trip  to  work  out  loss  of  trees  by  the  attack  of 
shelf  fungus  and  chestnut  canker.  A  field  trip  to  a  park  or  grove  near  home  may 
show  the  great  destruction  of  timber  by  these  means. 

a.   Shelf  Fungus 

Observations.  —  Count  the  number  of  perfect  trees  in  a  given 
area.  Compare  it  with  the  number  of  trees  attacked  by  the 
shelf  fungus.  Does  the  fungus  appear  to  be  transmitted  from 
one  tree  to  another  near  at  hand?  In  how  many  instances  can 
you  discover  the  point  where  the  fungus  first  attacked  the  tree? 
Do  healthy  trees  seem  to  be  attacked  ? 

Conclusion.  —  Under  what  conditions  will  shelf  fungus  attack 

a  tree? 

b.   Chestnut  Canker 

Note.  —  Chestnut  canker  is  spread  by  tiny  reproductive  bodies  called  spores. 
These,  if  they  obtain  a  foothold  on  a  sound  tree,  soon  grow  to  form  plants  which 
feed  upon  the  tree,  ultimately  causing  its  death. 

Observations.  —  In  a  given  area  are  all  the  chestnut  trees  dead 
or  dying?  How  might  tiny  spores  get  from  one  tree  to  another? 
What  appears  to  be  the  first  sign  of  the  disease  in  a  tree?  Pull  off 
the  bark  of  an  infected  tree  and  note  the  silvery  threads  running 
in  every  direction.  These  form  the  body  of  the  canker  called  the 
mycelium,  which  reaches  out  after  food.  What  part  of  the  tree 
would  it  be  likely  to  attack  and  why? 

NOTE.  — A  plant  or  animal  which  lives  at  the  expense  of  another  living  plant  or 
animal  is  called  a  parasite. 

Is  the  canker  a  parasite  ? 


112  PLANTS   WITHOUT   CHLOROPHYLL 

Conclusion.  —  1.  What  will  a  parasite  eventually  do  to  the 
host  on  which  it  lives  ? 

2.  Why  is  chestnut  canker  an  enemy  to  man  ? 

3.  Why  is  it  so  difficult  to  combat  ? 

Problem  8S :  To  determine  the  conditions  favorable  for  tlie 
growth  of  mold. 

Materials.  —  Four  wide-mouth  jars  or  bottles,  bread. 

Method.  —  Place  a  piece  of  bread  in  each  of  the  four  wide-mouth 
bottles  or  jars,  add  a  little  water,  and  expose  all  four  to  the  air  of 
the  living  room  or  kitchen  for  half  an  hour.  Then  cover  all  the 
jars  and  plunge  one  into  boiling  water  for  a  few  moments;  place 
this  and  a  second  jar  side  by  side  in  a  moderately  warm  room. 
Place  the  third  jar  in  the  ice  box  and  the  fourth  in  a  hot  and  dry 
place. 

Observations.  —  1.  Notice  day  by  day  any  changes  that  occur 
in  the  contents  of  the  jars. 

2.  In  which  jar  does  growth  appear  first? 

3.  Do  all  jars  have  a  like  growth  of  mold  at  the  end  of  a  given 
period  of  time? 

Conclusion.  —  1.    How  does  the  mold  get  on  the  bread? 

2.  Where  does  it  come  from? 

3.  Why  did  we  add  water  to  the  jars? 

4.  What  conditions  must  you  have  for  the  growth  of  mold  ? 

5.  Conversely,  how  would  you  keep  molds  from  getting  a  foot- 
hold on  foods  ? 

Problem  89:  To  study  the  structure  of  bread  mold. 
Materials.  —  Bread   mold.     Figure  page  133,  Civic  Biology. 

Note. — Directions  for  Growth  of  Mold.  —  Bread  mold  may  be  conveniently 
grown  for  laboratory  use  in  small  shallow  dishes  (Syracuse  watch  glasses,  Petri 
dishes,  or  butter  chips).  If  bread  is  exposed  to  the  air  for  a  few  minutes  and  then 
left  in  the  covered  dishes  for  a  day  or  two,  with  a  bit  of  wet  sponge  or  blotting 
paper  in  the  dish  to  keep  the  air  moist,  a  good  supply  of  mold  may  be  obtained  in 
a  convenient  dish  for  observational  purposes. 

Observations.  —  Examine  the  tangled  mass  of  threads  which 
cover  the  bread.  This  is  called  the  mycelium,  each  thread  being 
called  a  hypha.  How  do  the  hyphse  appear  to  be  attached  to  the 
bread  ? 


PROBLEM   90  113 

Note.  —  Somo  of  these  (hroads  rcticli  down  into  the  broad  and  art  as  iu.)i.->.  di- 
gestinf^  and  alxsorbing  nouri.shmonl.  These  arc  called  rhizoids.  Many  <if  the 
hyphae  are  prolonged  into  tiny  upright  threads,  bearing  at  the  top  a  little  ball.  Thi.s 
is  called  the  sporangium. 

With  the  low  power  of  the  microscope  the  structure  of  a 
sporangium  may  be  made  out.  The  dark-colored  ones  are  full 
of  ripe  spores,  which  may  be  seen  by  lightly  tapping  the  cover 
shp  over  the  slide.  How  do  the  spores  get  out  of  the  sporan- 
gium? Try  to  find  some  young  sporangia  and  note  the  differences 
in  size  and  color  between  them  and  the  older  ones. 

Conclusion.  —  1.    How  does  bread  mold  get  its  food? 

2.  How  do  you  know  that  it  cannot  manufacture  its  own  food? 
Explain. 

3.  Have  you  seen  any  other  kinds  of  molds  on  foods?  If  so, 
on  what  foods? 

4.  What  effect  do  molds  have  on  food? 

5.  What  are  the  spores  on  bread  mold  for? 

6.  What  effect  do  their  size  and  numbers  have  on  the  spread  of 
the  mold  ? 

Drawings.  —  Draw  a  series  of  sporangia  as  seen  under  the  low 
power. 

Problem  00 :  What  is  fermentation  and  what  causes  it  ? 

Materials.  —  Fermentation  tube,  yeast,  molasses,  test  tube, 
Erlenmeyer  flask,  limewater,  absorbent  cotton,  cork,  and  delivery 
tube. 

Method.  —  Carefully  fill  a  fermentation  tube  with  a  mixture  of 
molasses,  water,  and  a  little  piece  of  compressed  yeast  cake.  Plug 
the  open  end  with  absorbent  cotton.  Put  in  a  warm  place  over 
night.  Partly  fill  an  Erlenmeyer  flask  with  a  mixtun^  of  molasse's, 
water,  and  compressed  yeast  cake.  Close  the  flask  with  a  stopper 
fitted  with  a  delivery  tube  which  leads  into  a  test  tube  fillet!  with 
limewater. 

Observations.  —  What  has  happened  to  the  filled  end  of  the 
fermentation  tube?  Plow  do  you  account  for  (his'.'  Smell  the 
contents  of  the  flask  jifter  a  day  or  two.  What  is  this  odor? 
What  has  happened  to  the  limewater? 

HUNTER   LAB.    PROB.  —  8 


Ill  PLANTS   WITHOUT   CHLOROPHYLL 

Conclusion.  —  1.  What  happens  when  fermentation  takes  place? 

2.  What  gas  is  formed?     Explain  fully. 

3.  What  substance  is  present  in  the  flask?     How  do  you  know? 


T^  1  X  t  \x  ne  of  /- 
Ytast"^.!  Qucose 4  Alcohol 

^  Of  rvA 


Apparatus    to    prove    that    Alcohol   may   be    distilled    from    Fermenting 

Yeast. 

NOTE.  —  If  we  were  to  distill  off  the  contents  of  the  Erlenmeyer  flask,  we  could 
prove  the  presence  of  alcohol.  Fermentation  is  the  process  which  breaks  up  sugar 
(C12H22OU)  into  carbon  dioxide  (CO2)  and  alcohol  (C2H5OH). 


Trohle^n  91 :  To  learn  to  recognize  yeast  plants  under  the 
compound  microscope. 

Materials.  —  Compound  microscope,  nutrient  solution  con- 
taining growing  yeast  plants  from  a  compressed  yeast  cake  (com- 
posed of  food  and  yeast  plants),  iodine.  Lower  figure,  page  136, 
Civic  Biology. 

Method.  —  Place  a  drop  of  solution  on  a  slide  and  add 
iodine. 

Observations.  —  Note  the  dark  blue  bodies.  What  are  they? 
(Remember  the  iodine  test.)  The  smaller  ovoid  bodies  are  the 
yeast  cells.  What  color  are  they?  Shape?  Do  you  find  any 
budding  (one  growing  out  from  another  cell)  ?  Note  the  clear 
areas  {vacuoles)  within  the  cells. 

Conclusion.  —  1.  Write  a  paragraph  descriptive  of  yeast  cells 
and  their  method  of  reproduction. 

2.  Draw  a  few  cells  showing  budding.  Add  a  starch  grain  for 
comparison.     Draw  both  to  scale. 


PROBLEM  93  115 

Problem  92 :  Bo  yeasts  grow  wild  ? 

Materials.  —  Molasses  or  nutrient  solution,  Petri  dish,  fer- 
mentation tube. 

Method.  —  Place  a  Petri  dish,  or  other  flat  disii,  with  nu- 
trient solution  in  it  for  a  day  in  any  locality  exposed  to  ordinary 
drafts  of  air.  Then  pour  its  contents  into  a  fermentation  tube 
and  plug  with  absorbent  cotton. 

Observations.  —  Note  any  change  in  the  contents  of  the  closed 
end  of  the  tube. 

Conclusion.  —  1.  Is  there  any  yeast  present?  If  so,  where  did 
it  come  from? 

Note.  —  Spores  (reproductive  bodies)  of  yeast  are  found  in  the  air,  and  yeasts 
grow  on  grape,  apple,  pear,  and  other  fruit  skins. 

2.  What  causes  wine  to  ferment,  cider  to  become  hard  (ferment), 
etc.  ? 

Problem  93 :  To  determine  the  conditions  favorable  to  the 
growth  of  yeast. 

Materials.  —  Fruit  jars,  yeast  cake,  molasses. 

Method.  —  Label  three  pint  fruit  jars  A,  B,  and  C.  Add  one 
fourth  of  a  compressed  yeast  cake  to  two  cups  of  water  containing 
two  tablespoonfuls  of  molasses  or  sugar.  Stir  the  mixture  well  and 
divide  it  into  three  equal  parts  and  pour  them  into  the  jars.  Place 
covers  on  the  jars.  Put  jar  A  in  the  ice  box  on  the  ice  and  jar  B 
over  the  kitchen  stove  or  near  a  radiator;  boil  jar  C  hy  im- 
mersing it  in  a  dish  of  boihng  water,  and  place  it  next  to  B.  After 
forty-eight  hours,  look  to  see  if  any  bubbles  have  made  their 
appearance  in  any  of  the  jars. 

Observations.  —  Which  jars,  if  any,  show  bubbles  on  the  surface? 
After  bubbles  have  begun  to  appear  at  the  surface,  tlu*  fluid  in 
jar  B  will  be  found  to  have  a  sour  taste  and  will  smell  unpleasantly. 
The  gas  which  rises  to  the  surface,  if  collected  and  testeil,  will  be 
found  to  be  carbon  dioxide. 

Conclusion.  —  1.  What  conditions  are  favorable  for  the  growth 
of  yeast  ? 

2.  How  do  you  know  that  yeast  has  grown? 


116 


PLANTS   WITHOUT   CHLOROPHYLL 


Problem  94 :  What  are  the  conditions  favorable  for  the  growth 
of  yeast  in  bread  ?    ( Home  work. ) 

Materials.  —  Flour,  water,  sugar,  salt,  yeast  cake,  pans. 

Method.  —  Make  a  dough  by  mixing  flour,  sugar,  salt,  and  water 
in  proportions  to  make  a  thick  paste.  Knead  with  a  little  yeast 
which  has  previously  been  mixed  with  water.  Now  place  one  lot 
of  dough  in  the  ice  box,  one  at  the  temperature  of  the  room,  and 
one  in  a  warm  place  (over  90°  F.).  Later  bake  each  lot  and  use 
in  the  laboratory. 

Observations.  —  Which  of  the  three  lots  has  raised  the  most? 
Which,  after  baking,  has  the  best  appearance?  The  best  taste? 
What  makes  the  holes  in  the  bread  ? 

Conclusion.  —  L  What  caused  the  bread  to  rise? 

2.  Under  what  conditions  does  this  best  take  place? 

Experiments  with  yeast  may  be  continued  almost  indefinitely. 

For  excellent  suggestions,  see 
Conn's  Bacteria,  Yeasts,  and 
Molds  in  the  Home,  pp.  274-278. 


STERILIZING 

CHAMBER. 


1, 


Heat  applied  under  the  sterilizer  turns 
the  water  into  steam,  which  circulates 
through  the  holes  in  the  shelves,  es- 
capes between  Lhe  door  and  the  inner 
jacket,  and  returns  as  water  after  con- 
densing between  the  inner  and  outer 
jackets  of  the  steriUzer. 


JProblein  95 :  Hoiv  we  pro- 
ceed to  the  study  of  bacteria. 

Materials.  —  Dry  sterilizer, 
steam  sterilizer,  Petri  dishes, 
fermentation  tubes,  pipettes, 
and  compound  microscope. 

Several  pieces  of  apparatus 
are  useful  though  not  indispen- 
sable in  the  study  of  bacteria. 
All  of  this  apparatus  should  be 
shown  to  the  pupils  and  its  use 
explained.  Older  pupils  should 
be  encouraged  to  assist  in  pre- 
paring the  culture  media  and 
in  the  subsequent  sterilization 
of  the  material.  Sterilizers  may 
be  improvised  by  using  two 
pans,  one  of  which  fits  closely 


PROBLEM   Of)  117 

over  the  other.     Any  sheet-iron  or  tin  box  that  will  stand  heating 
red-hot  may  be  used  as  a  dry  sterilizer. 

Methods.  —  Study  the  construction  of  the  steam  and  dry 
sterihzers. 

NOTE.  —  Sterilization  moans  the  raising  of  the  temperature  to  such  a  degree  of 
heat  as  will  kill  all  germs. 

Conclusion.  —  How  is  the  sterilizer  fitted  to  do  its  work? 

Problem  96 :  How  to  prepare  culture  media. 

Method.  —  Beef  bouillon  which  has  been  cleared  and  filtered 
may  be  used  for  growing  bacteria. 

Nutrient  agar-agar^  is  the  best  medium  in  wliich  to  grow  bacteria. 
It  may  be  prepared  from  the  following  materials  :  1000  c.c.  water, 
10  g.  salt,  10  g.  peptone,  10  g.  Liebig's  beef  extract,  a  little  cooking 
soda,  and  10  g.  agar-agar.  If  agar-agar  cannot  be  obtained,  use 
100  g.  of  the  best  French  gelatin. 

Dissolve  the  beef  extract  in  the  1000  c.c.  water.  Cut  the  agar  into 
pieces  and  add  with  the  salt  and  peptone.  The  mixture  must 
then  be  heated  to  cause  the  agar  to  dissolve,  care  being  taken  that 
it  does  not  burn.  Enough  cooking  soda  is  added  to  cause  red 
litmus  paper  dipped  in  the  mixture  to  turn  ])lue,  i.e.,  the  liciuid 
should  be  faintly  alkaline.  Filtering  hot  agar  should  ha  carried 
on  within  the  steam  sterilizer.  A  glass  funnel  should  be  put  in  the 
mouth  of  an  Erlenmeyer  flask  and  one  or  two  layers  of  al^sorbent 
cotton  placed  within  the  funnel.  If  the  agar,  flask,  and  funnel  are 
kept  hot  within  the  sterilizer,  the  liquid  will  readily  pass  through 
the  cotton.  After  filtering,  the  mouth  of  the  flask  should  be  closed 
with  a  plug  of  absorbent  cotton.  Then  boil  in  ( he  cooker  for  half  an 
hour.  If  the  agar  mixture  is  not  clear,  it  shouUl  be  filtered  through 
cotton  a  second  time.  If  care  has  been  taken,  the  nutrient  solution 
is  now  ready  for  use,  and  may  be  set  aside  as  a  stock  solution. 

If  it  is  desired  to  make  a  nutrient  solution  for  molds,  omit  the 
cooking  soda  and  add  a  few  drops  of  dilate  liydrochloric  acid  ; 
because  molds  grow  best  in  a  slightly  acid  nuMliinii.  while  bacteria 
thrive  in  a  slightly  alkaline  medium. 

1  Agar-agar  is  a  preparation  from  seaweed  which  gives  an  excellent  vegetable 
gelatin  (a  protein  food). 


118  PLANTS   WITHOUT   CHLOROPHYLL 

To  prepare  the  nutrient  agar-agar  for  use,  it  may  be  poured  while 
hot  into  Petri  dishes  which  have  been  previously  sterilized  with  dry 
heat  for  several  hours  and  then  kept  in  a  dry  place  free  from  dust. 
It  is  well  to  sterilize  the  plates  once  or  twice  after  they  are  coated, 
using  a  steam  sterilizer. 

Test  tubes  partially  filled  with  the  nutrient  jelly  are  also  useful. 
Immediately  after  pouring  the  hot  jelly  into  the  test  tubes  they 
should  be  plugged  with  absorbent  cotton  and  then  placed  in  the 
steam  sterilizer. 

Proble^n  97 :  To  demonstrate  a  pure  culture. 

Materials.  —  Culture  media  in  Petri  dishes,  one  dish  containing 
colonies  of  bacteria ;  sterile  needle. 

Method.  —  The  instructor  transfers  some  of  a  colony  of  bacteria 
on  the  point  of  a  sterile  needle  to  the  sterile  surface  of  a  new  Petri 
dish  which  has  in  it  nutrient  jelly.  Watch  the  growth  of  the 
colony  on  subsequent  days. 

Observations.  —  How  long  before  colonies  appear  on  the  sur- 
face?    Are  these  colonies  all  alike  in  appearance? 

Conclusion.  —  Have  you  obtained  a  pure  culture?  If  so,  how 
did  you  do  this? 

To  THE  Teacher.  —  In  this  and  all  the  problems  that  follow,  the  teacher 
should  be  ready  to  start  the  experiments  at  least  three  or  four  days  before  they  are 
to  be  used  in  class  laboratory  for  demonstration.  Pupils  should  be  led  to  notice 
the  conditions  at  the  beginning  of  an  experiment  which  may  be  several  days  be- 
fore any  notes  or  drawings  are  expected  from  their  observations.  Interest  will  be 
held  by  discussing  beforehand  the  nature  of  the  problem  and  by  making  sure 
that  the  pupil  knows  the  aim  of  the  experiment.  Far  too  much  work  in  our  labora- 
tories is  blind,  unreasoning,  busy  work  following  directions  that  lead  nowhere. 
At  the  beginning  of  these  experiments  in  bacteriology,  the  instructor  should  make 
sure  by  demonstration  that  the  pupil  knows  what  to  work  for  on  a  plate  and  in  a 
tube.  The  making  of  a  pure  culture  should  be  shown,  not  so  much  because  it  will 
be  a  Tpure  culture  as  to  impress  at  the  start  the  need  for  extreme  care  in  making  all 
of  these  experiments.  Pupils  at  the  outset  should  be  taught  to  recognize  bacteria 
by  (a)  odor,  e.g.,  decay ;  (6)  change  in  appearance  of  nutrient  media,  e.g.,  cloudiness 
of  bouillon  ;  and  (c)  appearance  of  colonies.  Microscopic  demonstration  is  inter- 
esting but  unnecessary  with  young  students.  A  scale  drawing  on  the  board  or  on 
the  chart  means  much  more  to  the  average  pupil. 

Problem  98:  To  determine  where  bacteria  may  be  found. 
Materials.  —  A  number  of  covered  Petri  dishes  containing  sterile 
agar. 


PROBLEM   90 


no 


Method.  —  Expose  a  number  of  these  Petri  dishes  containing 
nutrient  for  the  same  length  of  time;  in  as  many  of  the  foUowinji; 
conditions,  and  as  many  others,  as  possiljle : 

(a)  to  the  air  of  the  schooh-oom. 

(6)  in  the  halls  of  the  school  while  })upils  are  passing. 

(c)  in  the  halls  of  the  school  when  pupils  are  not  moving. 

{d)  at  the  level  of  a  dirty  and  much-used  city  street. 

(e)  at  the  level  of  a  well-swept  and  little-used  city  street. 

(/)  in  a  city  park. 

(g)  in  a  factory  building. 

(h)  to  dirt  from  hands  placed  in  dish. 

(i)  to  contact  with  the  interior  of  the  mouth. 

(j)  to  contact  with  decayed  vegetable  or  meat. 

(k)  to  contact  with 
dirty  coin  or  bill. 

(I)  to  contact  with 
two  or  three  hairs 
from  pupil's  head. 

Observations.  — 
After  three  to  five 
days  note  the  condi- 
tions of  the  various 
plate  cultures.  Each 
day  count  the  num- 
ber of  spots  (colonies)  of  bacteria  and  molds  growing  on  the  cul- 
ture medium.     Make  a  table  like  the  above  to  show  your  results. 

Conclusion.  —  1.  Where  are  bacteria  found  in  greatest  num- 
bers? 

2.  What  are  the  factors  in  your  environment  by  means  of  whicli 
bacteria  might  get  to  your  body? 


Petri  Dish 

Expos  »<A 

Nvtrtxber  o^  Colonies     of 

irtctpr-ia 

5tk 

Hay 

6tK 
Defy 

rytW 
Day 

Box 

t)tlx 
DCTV 

lO'*^ 
Day 

Day 

I>oy 

A.ir   of 
Schoolroom 

©/"ScKool 

Quiet  Hell 
c   o/  School 

.  Bxcsy-City 

e    E-tc 

Problem  99 :  To  study  how  ra])i(lly  hnrteria  grow. 

Method.  —  Imagine  that  you  have  inhaled  a  germ  causing  cold 
or  consumption  {bacillus  tuberculosis)  while  riding  on  the  subway 
train  or  street  car  at  8.30  a.m.  You  arc  in  such  poor  physical 
condition  that  the  bacterium  can  grow  and  inultii)ly.  Scientists 
who  have  studied  germs  (bacteriologists)  tell  us  that  tiie  bacterium 


120  PLANTS  WITHOUT  CHLOROPHYLL 

causing  consumption  divides  every  half  hour.     Make  the  following 
table  complete  for  24  hours,  using  numbers  only. 

8.30  AM*  <^  Lctctcrii£JTv  tctlceiv.   ii\^              *-*  =1 

9.00     "     tke           ••               div-ldes            V—        ^  ,2 

9  30      "     tKe  Lctctericr   cLiv-icie  agaiiv —      — ,       , ^-      =  zj 

10.00     '•  "'^^     " ^--5 

10.30     "  ^16 

11.00    ••  .32 

11.30    •'  -64 

12.00    M-  =128 

12.30P>1-  --Z56 

etc  .,  ». 

Conclusion.  —  1.  How  many  bacteria  would  there  be  in  your 
lungs  at  8.30  a.m.  the  following  morning? 

2.  Why  do  we  not  catch  some  disease  each  day?  We  breathe, 
eat,  and  drink  countless  dangerous  bacteria  every  day.  (See  page 
154,  Civic  Biology.) 

Problem  100:  What  foods  are  preferred  hy  bacteria? 

Materials.  —  Raw  meat,  cooked  meat,  white  of  egg,  beans, 
Indian  meal  flour,  cake,  sugar,  butter,  test  tubes,  absorbent  cotton. 

Method.  —  Moisten  all  of  the  above  food  substances,  place  in 
test  tubes  with  a  little  water.  Expose  all  to  the  air  for  half  an 
hour.  (This  can  be  done  during  a  class  period.)  Plug  with  absorb- 
ent cotton  and  allow  to  stand  for  several  days. 

Observations.  —  Note  the  appearance  and  odor  of  the  various 
substances  after  five  days. 

Conclusion.  —  1.  In  which  substances  was  there  rapid  growth 
of  bacteria? 

2.  Can  you  make  any  generalization  with  reference  to  the  class 
of  nutrients  most  favorable  for  the  growth  of  bacteria? 

I*rohlem  101  •'  What  effect  has  heat  upon  the  growth  of 
bacteria  ? 

Materials.  —  Test  tubes,  bouillon. 

Method.  —  Number    four    tubes    containing    bouillon.     Place 


PROBLEM    103  121 

number  1  in  the  ice  box,  num})cr  2  in  a  dark  box  at  a  moderate  tem- 
perature, number  3  in  a  box  at  a  hot  temperature  (100°  F.  or  over), 
and  boil  number  4  for  15  minutes  and  then  place  with  number  2. 

Observations.  —  In  which  tube  does  the  greatest  amount  of 
growth  take  place?  (Note  the  odor  as  well  as  color  of  bouillon.) 
In  which  tube  did  the  least  growth  take  place? 

Conclusion.  —  What  is  the  effect  of  intense  heat  upon  bacteria? 

From  this  experiment  we  derive  the  very  important  mothnrl  of 
fighting  bacteria  by  means  of  sterilization.  From  experiments 
already  performed  give  a  definition  of  sterilization. 

Problem  102:    To  note  the  effect  of  moisture  and  drjjness 

upon  the  growth  of  bacteria.     ( Home  problem. ) 

Materials.  —  Beans,  test  tubes. 

Method.  —  Take  two  beans.  Remove  the  skin  and  crush  one. 
Soak  the  second  bean  overnight  and  then  crush  it.  Place  in  test 
tubes,  the  first  dry,  the  second  with  water.  Leave  both  in  a  warm 
place  for  two  or  three  days.     Then  smell  each  tube. 

Conclusion.  —  1.  In  which  is  decay  taking  place? 

2.  In  which  tube  are  bacteria  at  work  ?     How  do  you  know  ? 

Note.  —  Heat  and  dryness  are  thus  shown  to  be  unfavorable  to  the  growth  of 
bacteria.  From  experiments  dry  sterilization,  if  continued  long  enough  and  if  the 
heat  is  sufficiently  high,  seems  the  more  eflfective. 

Some  foods  are  spoiled  by  too  great  heat.  Milk,  in  particular, 
is  changed  by  boiling  so  as  to  be  quite  a  different  food.  Hence  a 
method  of  killing  germs  known  as  pasteurization  is  of  importance. 

Problem  103 :  To  determine  tlie  effect  of  pasteuri z option  upon 
the  keeping  quality  of  milk. 

Materials.  —  Milk,  two  sterilized  covered  jars,  thermometer, 
double  boiler,  or  pasteurizing  apparatus. 

Method.  —  Place  half  of  the  milk  in  a  sterilized  jar,  cover,  and 
leave  in  a  warm  place  for  24  to  48  hours. 

Place  the  remainder  of  the  milk  in  the  other  jar,  cover,  and  put  it 
in  the  double  boiler  or  pasteurizing  ai)paratus.  Bring  the  hot 
water  suriounding  the  jar  from   160°  to   180°  F.   for  about  30 


122  PLANTS   WITHOUT   CHLOROPHYLL 

minutes.  This  is  known  as  pasteurization.  Afterwards  treat 
exactly  as  you  did  the  first  jar  of  milk. 

Observations.  —  What  is  the  odor  of  milk  in  each  jar  after  24 
and  48  hours?  What  is  the  taste  of  the  milk  in  each  jar  after 
24  and  48  hours? 

Conclusion.  —  1.  What  are  found  in  milk  that  cause  it  to  sour? 
How  do  you  know? 

2.    What  is  the  use  of  pasteurization? 

Problem  104 :  How  to  care  for  milk  bottles  at  home. 

Materials.  —  Recently  used   milk   bottles. 

Method.  —  Place  a  recently  used  milk  bottle  in  a  warm  place 
for  24  hours.  Note  the  odor.  Rinse  out  a  second  milk  bottle 
with  cold  water,  a  third  with  boiling  water.  Set  aside  and  note 
odor  after  24  hours,  as  before. 

Observations.  —  Describe  the  odor.  Note  any  differences  in 
odor  in  the  three  bottles. 

Conclusion.  —  How  should  milk  bottles  be  treated  to  prevent 
rapid  souring  of  milk  ? 

Problem  105:  To  determine  the  bacterial  content  of  milh. 

Materials. — ^  Sterile  Petri  dishes  containing  agar  culture  media, 
a  sample  of  milk. 

Method.  —  Milk  should  be  collected  by  pupils  from  some  near-by 
source  as,  for  example,  the  lunchroom  of  the  school.  To  1  c.c.  of 
this  milk  add  19  c.c.  of  distilled  water  in  a  sterile  pipette.  Shake 
well  and  then  flood  the  surface  of  a  sterile  Petri  dish  with  the  mix- 
ture. Pour  off  all  excess  fluid.  Then  cover  quickly  and  place  the 
dish  in  a  moderately  warm  place. 

Observations.  —  Notice  that  after  24  hours  (or  even  less  if  the 
temperature  is  warm)  colonies  of  bacteria  appear  on  the  surface  of 
the  culture  media.  Note  the  number  of  colonies  of  bacteria 
present  on  the  second,  fourth,  and  sixth  days  after  preparing  the 
experiment. 

Conclusion.  —  1.  What  can  you  say  of  the  number  of  bacteria  in 
this  milk  ? 

2.  What  do  bacteria  do  to  the  milk  ?     (Smell  the  Petri  dish.) 


PROBLEM    106 


123 


Note.  —  A  similar  experiment  should  be  tried  with  water  from  various  sources. 
Hot  (led  (IrinkiiiK  water,  rain  water,  artesian  well  water,  tap  water,  and  water 
collectod  from  surface  pools  are  suggested  for  possible  experiments. 


Pf^obletn  100 

servatiues. 


To  determine  sortie  of  tlie  most  effective  pre- 


Materials.  —  Test  tubes  containing  beef  bouillon  and  various 
preservatives,  salt,  sugar,  vinegar,  formalin,  boracic  acid,  alcohol. 

Method.  —  Expose  the  tubes  to  the  air  unplugged.  Number  the 
tubes  and  label  them. 


To  No.  1  add  nothing. 

No.  2  add  J  spoonful  of  salt. 

No.  3  add  1  spoonful  of  sugar. 

No.  4  add  a  saturated  sugar  solution. 

No.  5  add  1  spoonful  of  vinegar. 

No.  6  add  a  few  drops  boracic  acid  (saturated  solution). 

No.  7  add  |  spoonful  boracic  acid. 

No.  8  add  5  drops  formalin. 

No.  9  add  1  spoonful  alcohol. 

Observations.  —  Note  the  appearance,  odor,  and  color  of  each 
tube  at  the  end  of  three  days,  five  days,  one  week,  and  two  weeks. 
Tabulate  your  results 
as  shown  in  accom- 
panying chart. 

Conclusion.  —  1. 
What  are  the  most  ef- 
fective preservatives? 

2.  Which  of  the 
above  are  permitted 
bylaw?  (See Hunter's 
Civic  Biology,  p.  148.) 

3.  On  which  solu- 
tions did  mold  grow? 

4.  Which  preservatives  prevented  bacteria  but  not  molds? 

5.  Which  preservatives  prevented  the  growth  of  l)oth  bacteria 
and  molds? 


Appeararvce 

anjO. 

Odor 

"1  i> 

I  0 

1;: 

5tC- 

•s 

a.  s 

At   £nd 

?/ 
3  Hays 

At  End 
5  ^ays 

At    End 
1  Week 

At  End 
2  "Weeks 

124 


PLANTS   WITHOUT   CHLOROPHYLL 


Prohleni  107:  To  determiiie  the  most  effective  disinfectants. 

Materials.  —  Use  tubes  of  bouillon  containing  different  strength 
solutions  of  formalin,  lysol,  iodine,  carbolic  acid,  and  bichloride 
of  mercury. 

Method.  —  Expose  all  tubes  unplugged  to  air,  having  previously 
inoculated  each  tube  with  germs  from  a  Petri  dish  culture.  Num- 
ber and  label  tubes. 

To  tube    1  add  1  drop  formalin. 

2  add  5  drops  formalin. 

3  add  1  drop  lysol. 

4  add  3  drops  lysol. 

5  add  1  drop  iodine. 

6  add  5  drops  iodine. 

7  add  4  drops  carbolic  acid. 

8  add  10  drops  carbolic  acid. 

9  add  1  drop  bichloride  mercury  solution. 
10  add  5  drops  bichloride  mercury  solution. 

Observations.  —  Tabulate  daily  for  a  week  or  more  the  results 
for  the  contents  of  each  tube  on  a  table  as  shown  below. 

Conclusion.  —  1.  Which  of  the  above  is  the  best  disinfectant? 

Why  do  you  answer 
as  you  do  ?  (Remem- 
ber that  according  to 
definition  an  antisep- 
tic may  retard  the 
growth  of  bacteria 
but  will  not  of  neces- 
sity kill  them ;  a  ger- 
77iicide  destroys  all 
bacteria  if  used  prop- 
erly; while  a  disinfect- 
ant is  a  solution  used  to  kill  disease  germs,  usually  in  the  excreta 
of  sick  people.) 

2.  Using  the  data  from  the  last  two  problems,  classify  the 
materials  used,  as  antiseptics,  germicides,  or  disinfectants.  Give 
reason  for  each. 


V\ppearancc 

Octoi-  at 
tke  E  i\d  of 

OS 

H  1^ 

ft." 

0  0 

?5 

«0M 

.'S 

3  d.ayg 

5  d-ctyfi 

l"week 

2  v^eeks 

REFERENCE  BOOKS 


1 25 


MOUD 

Yeast 

Bacteria 

Drawiriid 

Size 

Conditions 
Favorable 
ForGrov/lh 

Conditions 

Harinful 

ToGrov/th 

Use  to  Man 

Harm  to  Man 

Problem  Questions 

1.  Fill  out  the  accompanying  comparative  table  : 

2.  Where  may  mold  spores  be 
found?  What  must  they  have  in 
order  to  grow? 

3.  On  what  part  of  foods  do 
molds  grow? 

4.  How  would  you  prevent  mold 
spores  from  getting  into  food? 

5.  Is  food  that  has  become  moldy 
fit  to  eat  ?     Explain . 

6.  Why  are  we  able  to  eat  moldy 
jelly  after  removing  the  mold? 

7.  How  may  molds  be  harmful  to 
man?     Useful  to  man? 

8.  How  may  yeasts  be  useful  to  man? 

9.  Where  are  yeasts  found?     Give  proofs, 

10.  What  products  are  formed  when  bread  rises?  What  be- 
comes of  these  products? 

11.  It  is  said  that  yeast  plants  are  at  once  the  friends  of  man 
and  yet  make  him  their  slaves.     Explain  what  this  means. 

12.  Why  do  we  place  foods  in  the  ice  box? 

13.  Why  are  some  meats  and  fish  salted? 

14.  Why  are  some  meats  and  fish  smoked? 

15.  Why  is  corn,  wheat,  or  other  grain  stored  in  a  dry  place? 

16.  Why  do  canned  goods  keep? 

17.  Why  are  preserves  sometimes  not  fit  to  eat? 

18.  Why  do  we  place  eggs  in  salt,  liquid  glass,  or  coat  them  with 
paraffin  in  order  to  keep  them  ? 

19.  How  would  you  prevent  milk  from  souring? 

20.  What  would  you  do  to  prevent  the  possible  spread  of  <lis- 
ease  germs  in  your  home  if  you  had  a  case  of  typlioid  fever  tliere? 
Tuberculosis  ?     Grippe  ? 


Reference  Books 

Hunter,  Civic  Biology,  Chap.  XI,  American  liook  Company. 
Hunter,  Elements  of  Biology,  Chap.  XI.     American  Hook  Company. 


126  PLANTS   WITHOUT   CHLOROPHYLL 

Hunter,  Essentials  of  Biology,  Chap.  XI.     American  Book  Company. 

Atkinson,  Mushrooms,  Edible,  Poisonous,  etc.     Henry  Holt  and  Company. 

Bacteria  and  the  Nitrogen  Problem.  Reprint  Yearbook,  U.  S.  Department  of 
Agriculture,  1902. 

Bergen  and  Caldwell,  Practical  Botany,  Chap.  XI.     Ginn  and  Company. 

Bigelow,  Introduction  to  Biology.     The  Macmillan  Company. 

Bolduan,  Bacteriology  and  Your  Health,  Serums  and  Vaccines.  Scientific  American, 
June  14,  1913. 

Bowker,  Bacterial  Fertilizers.     Scientific  American,  February  14,  1914. 

Conn,  Agricultural  Bacteriology.     P.  Blakiston's  Son  and  Company. 

Conn,  Bacteria,  Yeasts,  and  Molds  in  the  Home.     Ginn  and  Company. 

Conn,  Story  of  Germ  Life.     D.  Appleton  and  Company. 

Coulter,  Barnes,  and  Cowles,  A  Textbook  of  Botany,  Vol.  I.     American  Book  Com- 

pany.  1 

Davison,  The  Human  Body  and  Health.     American  Book  Company. 

De  Bary,  Comparative  Morphology  and  Biology  of  the  Fungi,  Mycetozoa,  and  Bacteria. 
Oxford  University  Press. 

Duggar,  Fungous  Diseases  of  Plants.     Ginn  and  Company. 

Elliott,  Botany  of  To-day,  Chap.  IV.     Seeley  and  Company,  London. 

Frankland,  Bacteria  in  Daily  Life.     Longmans,  Green  and  Company. 

Goodhue,  Battle  of  the  Microbes.     Cosmopolitan,  February,  1913. 

Hendrick,  Exploring  the  Infinitely  Little.     World's  Work,  May,  1914. 

Hendrick,  Li^e  of  a  Microbe.     Literary  Digest,  April  11,  1914. 

Hendrick,  Longevity  of  Microbes.     Scientific  American,  January  3,  1914. 

Hitchens,  Sanitary  Bacteriology.     Science,  September  19,  1913. 

Hough  and  Sedgwick,  The  Human  Mechanism.     Ginn  and  Company. 

Kelly,  Walter  Reed  and  Yellow  Fever.     Doubleday,  Page  and  Company. 

Lipman,  Bacteria  in  Relation  to  Country  Life.     The  Macmillan  Company. 

Lyon  and  Byzzell,  Some  Conditions  Favoring  Nitrification  in  Soils.  Science,  Novem- 
ber 26,  1909. 

Marshall,  Microbiology  for  Agricultural  and  Domestic  Science  Students.  P.  Blakis- 
ton's Son  and  Company. 

McBride,  The  North  American  Slime  Molds.     The  Macmillan  Company. 

Muir  and  Ritchie,  Manual  of  Bacteriology.     The  Macmillan  Company. 

Newman,  The  Bacteria.     G.  P.  Putnam's  Sons. 

Overton,  General  Hygiene.     American  Book  Company. 

Prudden,  Dust  and  its  Dangers.     G.  P.  Putnam's  Sons. 

Prudden,  The  Story  of  the  Bacteria.     G.  P.  Putnam's  Sons. 

Ramsay,  Making  the  Microbe  Work.     Hearst  Magazine,  July,  1913. 

Ritchie,  Primer  of  Sanitation.     World  Book  Company. 

Rowe,  Raising  Germs  for  Profit.     Pearson's  Magazine,  April,  1910. 

Sedgwick,  Principles  of  Sanitary  Science  and  Public  Health.  The  Macmillan  Com- 
pany. 

Stevens,  Fungi  Which  Cause  Plant  Disease.     Science,  July  31,  1914. 

Thompson,  Our  Invisible  Allies.     Everybody's,  September,  1913. 

Thompson,  Pathologic  Bacteriology.     Science,  September  26,  1913. 

Winslow,  Characterization  and  Classification  of  Bacterial  Types.  Science,  January 
16,  1914. 

Winslow,  Evolution  of  Diseases.     Literary  Digest,  May  16,  1914. 


I 
J 


XII.   THE    RELATIONS    OF    PLANTS    TO    ANIMALS 

Problems.  — To  determine  the  general  biological  relations  tw- 
isting between  plants  and  animals. 

{a)  As  shown  in  a  balanced  aquarium. 
ib)  As  shown  in  hay  infusion. 

Suggestions  for  Laboratory  Work 

Demonstration  of  life  in  a  ''balanced''  and  ''unbalanced'^  aquarium.  — 
Determination  of  factors  causing  balance. 

Demonstration  of  hay  infusion.  —  Examination  to  show  forms  of  ani- 
mal and  plant  Life. 

Tabular  comparison  between  balanced  aquarium  and  hay  infusion. 

To  THE  Teacher.  —  The  gap  between  plants  and  animals  is  not  a  wide  one. 
The  bridging  of  the  gap  is  undertaken  by  means  of  the  exercises  which  follow. 
First  the  pupil  is  led  to  see  the  interdependence  of  organisms  on  the  earth ;  then 
the  dependence  of  one  kind  of  organism  upon  another ;  and  then  he  is  brought  face 
to  face  with  the  fact  that  there  are  two  kinds  of  organisms,  one  constructive,  the 
other  destructive.  These,  he  learns,  may  both  live  in  a  small  aquarium  jar  and 
they  may  both  be  single  cells. 

JProhlem  108:  To  study  some  biological  relations  of  plants 
and  animals  in  a  balanced  aquarium. 

Materials.  —  A  balanced  aquarium  containing;  livin«i;  ^iccn 
plants,  fish,  tadpoles,  snails,  and  other  forms  of  animal  life. 

Observations.  —  Watch  the  animals  within  the  aquarium  to  see 
if  any  are  feeding.  Note  what  they  eat,  also  that  the  fish  are 
continually  openinp;  their  mouths  as  if  hitinp;.  What  mij^ht  the 
fish  be  taking  from  the  water  (not  food)  ?  In  an  a(iuarium  placed 
in  the  sunlight,  what  gas  is  given  off  from  the  green  j^lants?  How 
might  this  gas  be  useful  to  animals? 

Does  this  explain  the  action  of  the  fish  mentioned  above  ?  What 
gas  is  given  off  by  animals  that  plants  would  use  under  certain 
conditions?     Are  these  conditions  present?    Fish  and  other  aiii- 

127 


128     THE  RELATIONS   OF   PLANTS  TO   ANIMALS 


mals  give  off  nitrogenous  wastes.     How  might  these  be  used  by 
the  plants  in  the  aquarium? 

Conclusion.  —  1.  What  might  the  plants  within  the  aquarium 
furnish  the  animals?  What  might  the  animals  furnish  the 
plants? 

2.    Remembering  that  the  sun  furnishes  energy,  tell  what  makes 

the  balance  within  the 
Balaivoed   A<jx* cerium.  aquarium.       How 

could     you     destroy 
this  balance? 

3.  Fill  out  the  ac- 
companying balance 
sheet. 

Problem  109 :  To  learn  what  we  mean  by  the  carbon  and 
the  oxygen  cycles. 

Method.  —  Carefully  study  the  following  figures. 


Contents 

Income  from. 

Ovitgo  to 

Aniiuals 

Plants 

• 

a.  Carbon  Cycle 

Observations.  —  In  the  plant  world  where  does  the  carbon  come 
from  ?  Trace  it  to  the  animals.  In  what  form  do  they  take  it  in  ? 
In  what  forms  do  they  release  it  ?  How  does  carbon  get  back  to 
the  plants? 

b.  Oxygen  Cycle 

Observations.  —  Begin  with  animals.  What  happens  to  oxygen 
within  their  bodies  ?     In  what  form  does  it  leave  the  animal  body  ? 


PRUBLE.M    HI 


129 


How  does  it  get  to  the  plant?     D()(\s  the  plant  use  oxyj^eii  as  the 
animal  does? 

Conclusion.  —  1.    How  are  plants  able    to   store    up    ener^;y? 
Where  does  it  come  from?     What  becomes  of  it? 

2.  Explain  the  carbon   cycle. 

3.  Explain  the  oxygen  cycle. 


idd  etc 


.Animal  Life 
)ecompQsing  Bacteria 


Problem  110 :  To  find  out  tlie  course  of  nitrogen  in  i/s  rela- 
tion to  plants  and  animals. 

Method. — Begin  at  the  point  of  the  diagram  marked  "  Free 
N/'  following  the  direction  of  the  arrows. 

Observations.  —  What 
do  we  mean  by  ''  free 
nitrogen"?  Where  is  it 
found?  How  do  green 
plants  get  the  free  nitro- 
gen? In  what  form  does 
the  nitrogen  get  into  the 
animal  body?  In  what 
form  does  the  nitrogen 
leave  the  bodies  of  ani- 
mals? What  causes  this  material  and  the  dead  bodies  of  animals 
to  become  usable  by  plants?  Does  any  nitrogen  get  back  into 
the  atmosphere  again?  If  so,  how  and  when?  Look  this  up  in 
any  good  book  of  reference. 

Conclusion.  —  1.   Fill  out  a  summarizing  table  like  the  accom- 
panying. 

2.  In  your  notebook 
exj)lain  in  a  well-writ- 
ten jiaragraph  what  is 
meant  bv  tlie  nitrogiMi 
cycle. 


y^/ti^ Nitrites 

«/j5    ates-* — Nitric  Bacteria 


l>laivts 


Gre.e.*v 


Ixvc  OTixe       of 
A.nirr»als    /rom 


Bacteria 


Owtgo       oj 

AlA  I  IIX  C\\  fi        to 


rrohlem  111:  To  prove  a  hay  infusion  is  an  unbalanced 
aquarium. 

Materials.  —  Hay,  glass  jar,  microscope,  glass  slides,  cover 
glasses,  and  pipette. 

HUNTEK    LAB.    PUGB. 9 


130      THE   RELATIONS   OF   PLANTS   TO   ANIMALS 

Method.  —  Make  ii  hay  infusion  by  placing  a  wisp  of  hay  in  a 
jar  of  wafni  wntcM".     Lot  it  stand  a  few  days. 

Observations.  —  What  has  happened  to  the  hay?  Any  change 
in  color?  Appearance?  Odor?  What  do  you  know  has  hap- 
pened to  materials  within  the  hay  infusion? 

With  a  l)ulb  pipette  take  a  drop  of  water  from  the  edge  of  the 
jar  near  the  surface  of  the  water.  Place  it  on  a  glass  slide. 
Examine  with  the  low  power  of  the  compound  microscope.  The 
tiny  structures  moving  about  are  one-celled  animals. 

Grass  for  hay  is  often  cut  near  pools  that  dry  up  at  haying  time. 
These  pools  contain  millions  of  one-celled  animals  (Protozoa)  which, 
as  the  pond  dries  up,  proceed  to  form  a  heavy  wall  about  each 
tiny  body.  In  this  form  (like  spores  of  mold)  they  may  be 
blown  about  in  dust  and  still  retain  their  vitality. 

Conclusion.  —  1.  What  does  the  presence  of  decay  in  the  hay 
infusion  indicate? 

2.  How  do  the  Protozoa  get  in  the  infusion? 

3.  On  what  might  the  Protozoa  feed  ? 

4.  Why  is  the  hay  infusion  unbalanced? 

5.  How  long  might  life  exist  in  it? 

Problem  Questions 

1 .  Why  is  an  aquarium  called  balanced  f 

2.  What  factors  are  necessarj^  for  the  balance? 

3.  What  are  the  food  relations  existing  between  plants  and 
animals  in  an  aquarium  ? 

4.  Compare  life  on  the  earth  to  a  balanced  aquarium. 

5.  What  kinds  of  bacteria  are  necessary  to  life  on  the  earth? 
Why? 

6.  What  substances  are  formed  through  the  influence  of  the 
bacteria  of  decay? 

7.  What  is  meant  by  the  carbon  cycle? 

8.  What  do  you  understand  by  the  oxygen  cycle? 

9.  Explain  the  nitrogen  cycle  in  an  aquarium;  on  the  earth. 
10.    W^hat  are  the  indispensable  bacteria?     Why? 

n.  In  what  stage  must  the  one-celled  animals  have  been  when 
they  were  attached  to  the  hay  ?     Why  ? 


REFERENCE  BOOKS  i:il 

Reference  Books 

Hunter,  Civic  Biology,  Cliap.  XII.     American  Book  Company, 

Hunter,  Elements  of  Biology,  Chap.  XII.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XI\'.     American  Book  Company. 

Abbott,  Elementary  Principles  of  General  Biology.     The  Macmillan  Company. 

Arnold,  77(c  Sea  Beach  at  Ebb  Tide.     Century  Company. 

Bateman  and  Bennett,  The  Book  of  Aquaria :  Part  I,  Frcsh-watcr  Aquaria;  Bart  II, 

Marine  Aquaria.     Charles  Scribner's  Sons. 
Bateman,  The  Vivarium.     Charles  Scribner's  Sons. 
Calkins,  Biology.     Henry  Holt  and  Company. 
Eggeling  and  Ehrenberg,   The  Fresh-water  Aquarium  and  its   Inhaftitants.     Henry 

Holt  and  Company. 
Furneaux,  Life  in  Ponds  and  Streams.     Longmans,  Green  and  Company. 
Hail,  The  Soil  as  a  Battle  Ground.     Harper's  Magazine,  October,  1910. 
Jones,  The  Aquarian  Naturalist.     Van  Voorst,  London. 
Kellogg,  Elementary  Zoology.     Henry  Holt  and  Company. 
Mayer,  Seashore  Life.     The  New  York  Aquarium  Nature  Series,  1905. 
Murbach,   Fresh-water  Aquaria.     .Journal  Applied  Alicroscopy,  September,    1900: 

also  American  A^aturalist,  March,  1900. 
Nevins,  The  Balanced  Aquarium.     Pearson's  Magazine,  October,  1907. 
Parker,  Biology.     The  Macmillan  Company. 

Rogers,  The  Salt-water  Aquarium,.     Country  Life  in  America,  July,  1904. 
Rogers,  Life  in  an  Aquarium,.     Teachers'  Nature  Study  Leaflets,   No.   11,  Cornell 

University,  April,  1898. 
Samuel,  The  Amateur  Aquarist.     Baker  and  Company. 
Sedgwick  and  Wilson,  Biology.     Henry  Holt  and  Company. 
The  Care  of  Balanced  Aquaria.     New  York  Zoological  Society  Bulletin  for  April, 

1903. 
Whedon,  The  Fresh-water  Aquarium.     Country  Life  in  America,  January,  1905. 


XIII.     SINGLE-CELLED  ANIMALS   CONSIDERED   AS 

ORGANISMS 

Problems,  —  To  deterinine  : 

(a)  How  a  one-celled  animal  is  hifiuenced  hy  its  environ- 
ment. 

(b)  How  a  single  cell  perforins  its  function. 

(c)  The  structure  of  a  single-celled  animal. 

Laboratory  Suggestions 

Laboratory  study.  —  Study  of  paramoecium  under  compound  micro- 
scope in  its  relation  to  food,  oxygen,  etc.  Determination  of  method  of 
movement,  turning,  avoiding  obstructions,  sensitiveness  to  stimuli.  Draw- 
ings to  illustrate  above  points. 

Laboratory  demonstrations.  —  Living  paramoecium  to  show  structure 
of  cell.  Demonstration  with  carmine  to  show  food  vacuoles  and  action 
of  cilia.  Use  of  charts  and  stained  specimens  to  show  other  points  of 
cell  structure.     Laboratory  demonstration  of  fission. 

To  THE  Teacher.  —  With  the  introduction  given  by  the  previous  chapter,  it  is 
easy  to  demonstrate  some  o£  the  reactions  of  a  single-celled  animal,  and  compare 
them  with  those  of  a  single-celled  plant.  The  structure  of  a  cell  and  its  various 
functions  as  an  organism  make  this  chapter  of  great  interest  to  all  pupils,  espe- 
cially as  the  wonders  of  the  world  of  the  microscope  are  placed  at  their  disposal. 

Problein  112:  To  study  a  one-celled  animal  in  order  to 
understand  better  {a)  its  reactions  to  stimuli;  ib)  the  cell  as  a 
unit  of  structure. 

Materials.  —  Hay  infusion,  pipette,  glass  slides,  cover  glasses, 
and  compound  microscope,  Kny  or  Leukart  charts. 

Method.  —  Remove,  by  means  of  a  pipette,  a  few  drops  of  the 
whitish  scum  on  the  top  of  the  hay  infusion.  This  scum  contains 
great  numbers  of  pararnoecia  (a  one-celled  animal).  Moimt  on  a 
slide  with  a  little  spirogyra  or  other  green  alga.  After  allowing 
slide  to  stand  for  a  few  moments,  examine  under  the  low  power. 

132 


PKORLE.M    112  i:« 

a.   Reaction   to  Stimuli 

Observations.  —  Do  tiie  moving  structures  appcur  to  luivc  any 
definite  shapes?  Do  they  move  with  any  definite  end  forward? 
Do  they  collect  in  any  locality  ?  If  so,  what  influences  them  to  do 
this?  Heat  a  needle  and  introduce  at  one  side  of  the  cover  ji;lass. 
Any  movement  on  the  part  of  the  paramoecia?  Notice  some  of 
the  animals  grouped  around  masses  of  food.  Why  do  you  suppose 
the  paramoecia  are  there?  Notice  other  paramoecia  with  refer- 
ence to  the  position  of  air  bubbles  or  to  threads  of  spiro^yi-a.  How 
do  they  He  with  reference  to  the  air  bubble?  What  mi^ht  the 
animal  get  from  the  air  bubble  if  it  is  to  do  work?  How  would 
a  cell  covered  with  a  membrane  take  anything  from  an  air  bubble? 
What  might  it  give  in  exchange? 

Note.  —  All  things  that  influence  a  plant  or  animal  to  react  are  called  stimuli. 

Conclusion.  —  1.  Write  a  paragraph  explaining  how  a  para- 
moecium  reacts  to  the  stimuli  in  its  environment. 
2.  Make  drawings  to  illustrate  your  conclusions. 

b.   Movement 

Observations.  —  Look  at  the  chart  or  at  the  prepared  material 
for  tiny  projections  from  the  body  walls  of  the  jxiranuecium. 
These  structures,  which  are  flexible  threads  of  living  matter,  are 
called  cilia. 

Conclusion.  —  How  might  locomotion  be  accomplished  by 
means  of  cilia?     Explain  with  the  aid  of  a  diagram. 

c.  Internal    Structure 

Observations.  —  To  study  the  internal  structure  of  jjaramaH-ia 
use  living  animals  which  have  been  fed  on  green  microscopic 
plants  or  on  carmine  grains.  Examine^  with  high  |)ower  and  also 
use  charts.  The  small  round  spaces  filled  with  green  plant  mate- 
rial or  with  red  carmine  grains  are  food  racuolcs.  Look  for  a  groove 
on  one  side  of  the  cell;  this  leads  into  a  funnel-like  oi)ening,  the 
gullet  (g).  (See  page  134.)  Explain  how  food  might  be  takcMi  in 
by  a  paramoecium.     How   might    it   circulate  within  tlu^  body? 


134     SINGLE-CELLED   ANIAL\LS   AS   ORGANISMS 


i^iw-oelD  ex 


71 


'■:<y;m^ 


m\m\\'\J 


iirii'iii-i  ■!  1  iiliV,\v>Tkr'4 


"'l"""" 


P*  cir»  ct  rrv  oe  oi  ^trrv 


"Voi^t ic  ell 


cc 


Remember  that  the  paramoecium 
is  a  semi-fluid  body,  covered  with 
a  membrane. 

Other  structures  found  within 
the  cell  are  (1)  contractile  vacuoles 
(cv) ,  usually  one  at  each  end  of  the 
cell ;  these  serve  to  excrete  liquid 
waste ;  (2)  water  vacuoles,  clear 
spaces;  (3)  the  nucleus  (n),  con- 
sisting of  a  double  structure,  the 
micro-  and  the  macro-nucleus 
which  can  be  seen  only  in  a 
stained  specimen.  (Demonstra- 
tion.) 

Conclusion.  —  L  What  struc- 
tures are  found  in  a  one-celled 
animal  ? 

2.  What  uses  have  these  struc- 
tures ? 

3.  Draw  a  paramoecium  show- 
ing all  structures. 


A  Colonial  Type 


d.  Reproduction 

Observations.  —  Sometimes 
paramoecia  may  be  found  divid- 
ing crosswise  by  fission.  In  this 
process  each  of  the  two  new  cells 
formed  contains  half  the  original 
nucleus  and  half  of  the  rest  of 
the  cell  body.  Draw  such  a  specimen  if  3^ou  find  one.  In 
another  method  of  reproduction,  parts  of  the  nuclei  of  two 
adjoining  cells  become  exchanged,  so  that  the  first  cell  has  part 
of  the  nucleus  of  the  second  cell  and  the  second  cell  has  part 
of  the  nucleus  of  the  first  cell.  This  is  known  as  conjuga- 
tion. 

Conclusion.  —  L  How  do  paramoecia  reproduce? 

2.  What  is  the  difference  between  fission  and  conjugation? 


REFERENCE  BOOKS  135 

Problem  ll'i :  Cm)V])aratJve  stitfhjof  rarious  fnmvfiof  siti^le- 
ceUecl  atUmals  to  cxplaiiv  division  of  labor.    (Kxtra  Problem.) 

Materials.  —  Figures  on  opposite  page  showing  amoeba,  paranioe- 
cium,  vorticella,  and  a  colonial  form,  such  as  charchesium  or  zoo- 
thamnium. 

Observations.  —  Examine  the  figure  of  an  amoeba.  Are  there 
any  special  structures  for  locomotion?  The  entire  cell  body 
changes  shape  as  the  animal  moves.  Has  the  animal  any  definite 
mouth?  Gullet?  Look  at  the  figures.  How  is  food  taken  into 
the  body?     Look  for  food  vacuoles,  contractile  vacuoles,  nucleus. 

Compare  an  amoeba  with  a  paramoecium.  In  which  cell  is 
the  work  performed  by  more  separate  parts  of  the  cell  ? 

NOTE.  —  The  performance  of  different  kinds  of  work  by  dififercnt  structures  in 
a  plant  or  animal  is  called  division  of  labor. 

Compare  the  amoeba  and  paramoecium  with  vorticella.  Note 
the  stalk;  it  is  contractile.  Is  the  entire  body  covered  with 
cilia?  Are  the  cilia  used  for  the  same  purpose  as  in  paramoecium ? 
Is  there  a  definite  food  opening?  How  does  food  get  into  this 
opening?  (Demonstration  of  a  vorticella  in  a  weak  carmine  mix- 
ture will  show  this  point.) 

Look  at  the  colonial  form.  How  does  it  differ  from  vorticella? 
How  does  it  move?  How  is  food  obtained?  Is  there  greater  or 
less  division  of  labor  than  in  a  single  cell  ? 

Conclusion.  —  What  is  division  of  lal)or?  Explain  from  com- 
parison with  at  least  three  one-celled  animals. 

Problem  Qu?:stions 

1.  Explain  the  term  "  reaction  to  stimuli  "  with  reference  to 
paramoecium. 

2.  What  parts  of  a  cell  are  found  in  paramoecium  ? 

3.  How  does  paramoecium  move?  Feed?  Breathe?  Re- 
produce ? 

4.  How  is  division  of  labor  illustrated  among  the  Protozoa? 

Refehence  Books 
Hunter,  Ciinc  Biology,  Chap.  XIII.      AmericMM  iiook  ('()mi»:tiiy. 
Hunter,  Elements  of  Biology,  Chap.  XII.     American  Book  Company. 


136      SINGLE-CELLED   ANIMALS   AS   ORGANISMS 

Hunter,  Essentials  of  Biology,  Chap.  XV.     American  Book  Company. 

Calkins,  Protozoology.     Lea  and  Febiger. 

Calkins,  The  Protozoa.     The  Macmillan  Company. 

Davison,   Human  Body  and  Health,  Advanced,  Chap.  XXIII.     American    Book 

Company. 
Guyer,  Animal  Micrology.     University  of  Chicago  Press. 
Jennings,  Study  of  the  Lower  Organisms.     Carnegie  Institution  Report. 
Jordan,  Kellogg,  and  Heath,  Animal  Studies.     D.  Appleton  and  Company. 
Macfadyen,  The  Cell  as  the  Unit  of  Life.     P.  Blakiston's  Son  and  Company. 
Parker,  Lessons  in  Elementary  Biology.     The  Macmillan  Company. 
Ritchie,  Primer  of  Sanitation,  Chap.  XXVI.     World  Book  Company. 
Shannon,  The  Microscopic  Animals  of  the  Sea.     Harper's  Magazine,  June,  1910. 
Sharpe,  Laboratory  Manual  in  Biology,  pp.  140-143.     American  Book  Company. 
Wilson,  The  Cell  in  Development  and  Inheritance.     The  Macmillan  Company. 


J 


XIV.   DIVISION  OF  LABOR.     THE  VARIOUS  FORMS  OF 

PLANTS   AND   ANIMALS 

Probletns.  —  The  development  and  forms  of  jilants. 

The  development  of  a  simple  animal. 

What  is  division  of  labor  ?    In  what  does  it  result  ? 

How  to  know  the  chief  characters  of  some  great  animcd 

groups. 

Laboratory  Suggestions 

A  visit  to  a  botanical  garden  or  laboratory  demonstration.  —  Some  of  the 
forms  of  plant  life.  Review  of  essential  facts  in  development  of  bean  or 
corn  embryo. 

Demonstration.  —  Charts  or  models  showing  the  development  of  a  many- 
celled  animal  from  egg  through  gastrula  stage. 

Demonstration.  —  Types  which  illustrate  increasing  complexity  of  body 
form  and  division  of  labor. 

Museum  trip.  —  To  afford  pupil  a  means  of  identification  of  examples 
of  principal  phyla.  This  should  be  preceded  by  objective  demonstration 
work  in  school  laboratory. 

To  THE  Teacher.  —  The  object  of  this  chapter  is  to  Rive  the  pupil  a  bird's-eye 
view  of  the  plant  and  animal  kingdoms.  This  is  not  done  for  the  sake  of  accurate 
classification,  but  simply  to  impress  him  with  the  wonderful  diversity  and  com- 
plexity of  form  and  structure  in  the  living  world  about  him.  Also  those  exercises 
should  bring  home  the  idea  that  division  of  labor  and  complexity  of  structure  in 
plants  and  animals  go  hand  in  hand.  The  exercise  in  determining  the  place  of 
animals  and  plants  in  the  evolutionary  scale  should  be  largely  an  exercise  in  deter- 
mining the  amount  of  division  of  labor  shown  in  a  given  group.  It  is  needless  to 
say  that  the  work  can  best  be  done  by  means  of  typo  collections  in  a  museum  or  in 
the  laboratory.  The  outline  (Problem  US)  in  the  hands  of  the  pupils  aids  in  the 
identification  of  the  various  phyla.  Comparison  of  type  forms  under  these  phyla 
gives  the  pupil  an  excellent  opportunity  for  study  of  relation  of  forms. 

Problem  114:  How  the  plant  kingdom  is  classified. 
Materials.  —  Specimens    of    algae,    fungi,    mosses,    ferns,    and 
flowering  plants. 

Note.  — All  animal  and  plant  life  shows  greater  <»r  le.s.s  divi.sion  of  lalior.  the 
more  complex  forms  showing  greater  division  of  labor.  We  classify  as  hightr  the 
plants  or  animals  showing  greater  division  of  labor. 

137 


138  DIVISION   OF  LABOR 

a.  Algae 

Method  and  Observations.  —  Examine  some  pond  scum  with  a 
hand  lens.  What  kind  of  body  has  the  plant?  Has  it  any  root, 
stem,  and  leaves?  Look  at  specimens  under  the  microscope  and 
on  the  chart  to  determine  the  methods  of  reproduction. 

Conclusion.  —  1.  Would  such  a  plant  as  this  have  much  divisi'on 
of  labor?     Many  different  organs? 

2.  How  does  such  a  plant  reproduce  ? 

b.  Fungi 

Method  and  Observations.  —  You  have  already  studied  a  yeast 
and  a  mold  as  examples  of  fungi.  Study  in  addition  a  shelf  fungus. 
Remember  that  the  shelf-like  part  is  the  reproductive  portion 
(much  like  the  sporangium  and  stalk  of  black  mold).  Study  a 
piece  of  decayed  wood  containing  mycelium  of  bracket  fungus. 
What  is  its  general  appearance  ?     Compare  with  mycelium  of  mold. 

Conclusion.  —  Is  division  of  labor  greater  in  the  algae  studied 
or  in  the  fungi  studied  ?     Explain  fully. 

c.  Mosses 

Method  and  Observations.  —  Notice  that  the  body  of  the  moss 
shows  rootlike  structures,  rhizoids ;  an  upright  stem ;  and  leaf- 
like structures.  Notice  that  some  bear  stalks  with  a  little  capsule 
on  the  top.  The  stalk  and  capsule  bear  asexual  spores  and  are 
known  as  the  asexual  generation.  The  moss  plants  produce  egg 
and  sperm  cells  in  different  organs,  giving  the  title  of  sexual 
generation  to  this  part  of  the  plant. 

Conclusion.  — ■  Does  the  separating  of  the  plant  into  two  phases, 

a  sexual  and  an  asexual  phase,  result  in  greater  or  less  division  of 

labor?     Explain. 

d.  Ferns 

Method  and  Observations.  —  The  fern  plant  has  roots,  an 
underground  stem,  and  large  leaves  called  fronds.  On  the  backs 
of  some  of  the  fronds  are  found  asexual  spore-producing  bodies, 
sporangia.  The  sexual  part  of  the  fern  (see  chart)  is  a  very  tiny 
body  called  a  prothallus. 


PROBLEM    lir,  IM) 

Conclusion.  —  ronipiire  the  ferns  with  other  plants  in  com- 
plexity of  structure. 

e.  Flowering  Plants 

Method  and  Observations.  —  In  the  llo\verin«i  i)lants  the  sexual 
generation  is  reduced  to  a  very  small  part  of  the  flower,  the  stamens 
and  pistil.  What  structures  found  tlierein  make  tliis  the  sexual 
generation?  All  the  rest  of  a  plant  —  root,  stem,  leaves  —  is  the 
asexual  generation. 

Conclusion.  —  1.  Compare  the  various  structures  of  a  llowering 
plant  with  those  of  the  fern,  moss,  fungus,  and  alga. 

2.  Show  that  division  of  labor  is  greatest  in  tlie  flowering  plant. 

f.  Physiological  Development 

Refer  back  to  your  work  on  the  function  of  the  flower.  At 
the  time  of  fertilization,  how  many  cells  make  up  the  young  plant? 
What  happens  to  it  as  it  grows  into  an  embryo  ?  Is  an  embryo  a 
more  complex  structure  than  an  egg?  Why?  Tn  the  above  forms 
is  the  development  of  this  young  plant  in  any  way  similar?  (See 
charts  or  text  figures.) 

General  Conclusion.  —  1.  What  group  of  plants  studied  has 
the  most   complex  structure?     The  greatest   division   of  labor? 

2.  Is  there  any  connection  between  the  position  of  a  jilant  in  the 
plant  kingdom  and  its  complexity  of  structure?     Explain. 

Problem  115:  To  compare  reproduction  in  plants  witli  that 
in  animals. 

Materials.  —  Charts  and  models  illustrating  processes  of 
fertilization  and  development  in  plants  and  animals. 

Method.  —  Compare,  by  means  of  charts,  fertihzation  in  several 
types  of  plants  with  that  in  some  simi)le  animal.  Use  models 
illustrating  early  development  of  amphioxus,  fish,  and  frog. 

Observations.  —  How  does  fertilization  take  place  in  a  flower- 
ing plant?     In  a  fern?     In  a  moss?     In  a  very  simple  i)lant  ? 

By  what  means  does  the  sperm  cell  get  to  the  egg  cell  in  each 
of  the  above  cases?  Is  there  any  outside  agency  that  helps  in 
this? 


140  DIVISION   OF   LABOR 

NOTE.  —  In  animals,  as  in  plants,  two  cells,  the  sperm  and  the  esp:,  unite  to 
form  a  fertilized  egg.  This  cell  will,  under  favorable  conditions,  develop  into  a 
uew  animal. 

In  animals,  which  is  the  larger,  sperm  or  egg  cell  ?  Which  is  the 
movable  cell?  Suppose  an  animal,  as  a  fish,  laid  its  eggs  in  the 
water,  how  might  fertilization  take  place? 

NOTE.  —  The  embryo  of  a  plant  (e.g.,  the  bean  seed)  grows  as  the  result  of  the 
division  of  the  original  fertilized  egg  into  first  two,  then  four,  then  eight,  etc.,  cells. 
An  animal  embryo  develops  in  a  similar  manner. 


Arrange  models  in  order  to  show  development  from  a  single  cell 
(the  fertilized  egg)  to  a  hollow  ball  of  cells,  called  the  blastula 
stage.  (See  figures  above.)  Note  what  happens  next  in  develop- 
ment. The  cup-like  structure  is  called  a  gastrula.  How  is  the 
gastrula  stage  formed? 

NOTE.  —  Most  animals,  including  man,  pass  through  the  stages  shown  above. 

Suppose  that  all  the  cells  had  ciHa  in  the  blastula  stage.  How 
would  locomotion  take  place  ?  Suppose  the  hollow  of  the  gastrula 
is  used  as  a  food  tube.     Is  there  then  any  division  of  labor? 

Conclusion.  —  1.  In  what  respects  is  fertilization  similar  in 
plants  and  in  animals? 

2.   What  stages  of  development  are  alike  in  all  animals? 

Problem  JIG:  To  study  the  division  of  labor  in  tissues  and 
organs. 

Materials.  —  Charts  and  slides  showing  different  kinds  of 
tissues,  microscope. 

Method  and  Observations.  — We  have  already  found  that  cells 
having  the  same  structure  and  performing  the  same  work  form 
tissues.  Examples  in  our  bodies  are  muscle  tissue,  nerve  tissue, 
connective  tissue,  etc.  Does  a  blastula  have  more  than  one  tissue? 
A  gastrula?     Give  reasons  for  your  answers. 

Examine  figure,  page  179,  Civic  Biology,  or  slides  showing  different 


PROBLEM   118  111 

kinds  of  cells,  such  as  muscle,  nerve,  and  l)one.     Why  do  we  have 
different  tissues  in  a  plant  or  in  an  animal  ? 

Note.  —  The  hand  is  an  organ,  a  structure  made  up  (jf  different  tissues,  all  of 
which  work  together  for  the  performance  of  certain  work. 

Name  some  organ  found  in  an  animal;  in  a  plant.  Name 
some  tissues  that  make  up  your  hand  ;  your  foot ;  your  eye.  (Use 
your  Civic  Biology,  pages  266-271,  for  this  purpose.) 

Conclusion.  —  1.    Why  are  cells  of  different  shapes  and  sizes? 

2.  Of  what  purpose  are  tissues  in  our  body? 

3.  Why  are  organs  composed  of  tissues?  Use  the  term  division 
of  labor  in  writing  your  answer. 

Probletn  117 :  To  find  some  of  the  functions  common  to  all 
aniinals. 

Method.  —  Review  the  needs  of  a  single-celled  animal.  What 
must  a  single-celled. animal  do  in  order  to  live? 

NOTE.  —  Remember  that  food  must  be  obtained,  digested,  and  oxidized  to  re- 
lease energy  (in  a  many-celled  animal  this  food  must  be  circulated  about  the  ani- 
mal). Some  of  it  must  be  made  into  living  matter,  and  wastes  must  be  excreted 
from  the  body. 

What  organs  has  a  single-celled  animal  that  perform  each  of 
these  functions?  Compare  the  needs  of  a  paramoecium  with  (mr 
needs.  Compare  the  functions  of  a  paramoecium  with  our  func- 
tions. Compare,  in  each,  the  organs  which  perform  these  func- 
tions so  far  as  you  know  them.  Get  assistance  from  j-our  text- 
book   {Civic   Biology,    pages    180,  181). 

Conclusion.  —  How  does  a  single-coll(Ml  animal  compare  with  a 
very  complex  animal  in  the  number  of  function.s  and  in  tlie  organs 
it  has  for  performing  these  functions? 

Problem  US'  How  to  know  some  tyf)es  of  animcils  in  the 
animal  kingdom. 

Materials.  —  Dried  or  formalin  spiM-imens  of  sponge,  se^i 
anemone,  starfish,  segnuMited  worms,  crust  a('(>ans,  iiiscM'ts, 
mollusks,  and  vertebrates  (fish,  frog,  turtle,  l)ird,  and  manunal). 


142  DIV1810N   OF   LABOR 

Groups  of  Animals 

Note.  —  Animals  may  be  arranged  in  an  e\'olution£.ry  series  beginning  with 
simple  forms  and  ending  with  very  complex  forms,  such  as  man.  Division  of  labor 
in  a  steadily  increasing  degree  is  seen  as  we  go  from  the  simple  to  the  higher  forms. 
We  shall  try  to  arrange  the  forms  given  in  an  evolutionary  series,  beginning  with  the 
simplest  forms  and  working  up  to  the  most  complex. 

a.  Protozoa 

First  would  come  one-celled  animals,  Protozoa.  Name  three 
Protozoa  which  you  have  studied. 

b.  Porifera 

Sponges,  Porifera  (containing  pores) .  Examples  :  bath  sponge, 
Grantia.  Simple  fixed  forms.  Note  a  specimen  of  the  bath 
sponge.  Has  it  a  skeleton?  What  is  the  internal  structure  of  a 
sponge?     (See  figure  on  page  180,  Civic  Biology.) 

c.  Coelenterates 

Coelenterates  (Coelom  =  body  cavity,  enter  on  =  food  tube). 
Examples :  Hydra,  sea  anemone,  jellyfish.  There  is  a  single 
cavity  in  the  body  with  one  opening.  (See  figure  on  page  179, 
Civic  Biologij.)  The  animals  in  this  group  are  provided  with  sting- 
ing cells. 

d.   Segmented  Worms 

Examples  :  sandworm,  earthworm.  Long  jointed  or  segmented 
animals  with  or  without  jointed  legs.  Nervous  system  on  the 
under  side  of  the  body.     (Pages  183,  184,  Civic  Biology.) 

e.  Echinoderms 

Examples :  starfish,  sea  urchin.  These  animals  have  spines  in 
the  skin,  body  organs  more  complicated.  (Pages  184,  185, 
Civic  Biology.) 

f.  Arthropods 

Having  jointed  body,  jointed  appendages,  and  outside  skeleton. 
Nervous  system  on  under  side  of  the  body.  There  are  two  great 
groups  of  these  animals: 


PROBLEM   QUESTIONR  113 

(a)  Crustacea.  Limy  skeleton,  sej^mciifecl.  Ixxly  divided  inlo 
two  regions,  more  tlum  three  pairs  of  walkirij;  appendages,  breathe 
througli  gills.     Examples:  erayiish,  crab,  lobster. 

(6)  Insecta.  Having  a  horny  skeleton  (ehitin),  only  three 
pairs  of  walking  legs,  breathe  through  traehea\  Examples:  bee, 
ant,  grasshopper.  Two  smaller  groups  of  Aithrojxxls  arc  also 
found:  the  Arachnids,  spiders,  having  four  jjairs  of  legs,  and  tiu^ 
Myriapods,  "  thousand  leggers,"  which  have  many  pairs  of  simi- 
lar jointed  legs.     (Page  185,  Civic  Biology.) 

g.   Mollusks 

Examples:  clam,  snail,  oyster.  Have  a  soft,  unjointed  body, 
usually  covered  with  a  hard  limy  shell  of  one  or  two  pieces  (valves). 
This  shell  is  formed  by  a  covering  called  the  mantle.  These  ani- 
mals breathe  through  gills.     (Page  185,  Civic  Biology.) 

h.  Vertebrates 

Examples  :  fish,  frog,  turtle,  bird,  dog.  Having  an  internal  limy 
skeleton  composed  of  pieces  of  bone  jointed  together.  Also  an 
external  skeleton  which  may  be  scales,  bone,  feathers,  nails,  or 
hair.  Breathe  by  gills  or  lungs.  Central  nervous  system  on  back 
or  dorsal  side  of  body  protected  by  a  chain  of  bones  called  the 
vertebral  column.     (Pages  185-192,  Civic  Biology.) 

Method  and  Observations.  —  Using  the  above  dinv'tions  pick 
out  of  the  material  given  you  one  specimen  of  each  group  and 
arrange  the  specimens  selected  in  a  series  showing  evolutionary 
order. 

Conclusion.  —  1.    What  do  you  mean  by  evolutionary  order? 

2.  Has  division  of  labor  anything  to  do  with  your  placing  these 
specimens  as  you  have? 

Problem  Questions 

1.  Why  do  we  speak  of  t\w  plant  or  animal  kingdom^ 

2.  What  results  from  fertilization  in  both  plants  and  animals? 

3.  How  are  egg  cells  protected  in  birds?  In  a  flower?  W  liy 
should  they  be  protected  ? 


144  DIVISION   OF   LABOR 

4.  How  does  nature  make  up  for  lack  of  protection  of  the  eggs 
of  fishes  ?     (See  Civic  Biology,  pages  238-239.) 

5.  What  is  division  of  labor? 

6.  What    is    a    blastula?     A    gastrula?     An    embryo?     Give 
examples. 

7.  What  is  a  tissue ?     An  organ? 

8.  What  are  the  functions  necessary  for  all  animals  ? 

9.  How  are  these  functions  performed  in  a  single-celled  animal  ? 
In  a  many-celled  animal  ? 

10.  What  do  we  mean  by  evolutionary  order? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XIV.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chap.  XVI.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XVI.     American  Book  Company. 

Adams,  Guide  to  Study  of  Animal  Ecology.     The  Macmillan  Company. 

Comstock,  Manual  for  Study  of  Insects.     Comstock  Publishing  Company. 

Comstock,  The  Spider  Book.     Doubleday,  Page  and  Company. 

Davenport,  Introduction  to  Zoology.     The  Macmillan  Company. 

Fabre,  Life  of  the  Fly.     Dodd,  Mead  and  Company. 

Fabre,  Life  cf  the  Spider.     Hodder  and  Stoughton. 

Fabre,  Social  Life  in  the  Insect  World.     T.  Fisher  Unwin. 

Flower,  The  Horse.     D.  Appleton  and  Company. 

French,  The  Butterflies  of  the  Eastern  United  States.     J.  B.  Lippincott  Company. 

Hahn,  Hiberyiation  of  Animals.     Popular  Science  Monthly,  February,  1914. 

Harmer  and  Shipley,   The  Cambridge  Natural  History.     Vol.  V.     The  Macmillan 

Company. 
Herrick,  Household  Insects  and  Methods  of  Control.     Cornell  Reading  Courses. 
Holland,  The  Butterfly  Bock.     Doubleday,  Page  and  Company. 
Holland,  The  Moth  Book.     Doubleday,  Page  and  Company. 
Hornaday,  Our  Vanishing  Wild  Life.     New  York  Zoological  Society. 
Hornaday,  American  Natural  History.     Charles  Scribner's  Sons. 
Hough  and  Sedgwick,  The  Human  Mechanism.     Ginn  and  Company. 
Howard,  The  Insect  Book.     Doubleday,  Page  and  Company. 
Kellogg,  Elementary  Zoology.     Henry  Holt  and  Company. 
Kingsley,  The  Comparative   Anatomy  of    the  Vertebrates.      P.  Blakiston's  Son  and 

Company. 
Linville  and  Kelly,  Textbook  in  General  Zoology.     Ginn  and  Company. 
Maeterlink,  Life  of  the  Bee.     Dodd,  Mead  and  Company. 
Miall,  Aquatic  Insects.     The  Macmillan  Company. 
Miller,  Butterfly  and  Moth  Book.     Charles  Scribner's  Sons. 
Miner,  Animals  of  the  Wharf  Piles.     American  Museum  of  Natural  History. 
Miner,  Sea  Worm  Group.     American  Museum  of  Natural  History. 
Needham,  Elementary  Lessons  in  Zoology.     American  Book  Company. 


REFERENCE   BOOKS  1  i:, 

Parker  and  Haswell,  Manual  of  Zoology.     The  Maciiiillari  ("otiipany. 

Porterrf,  Wild  Beasts.     Charles  Seribner's  Sons. 

Pycraft,  Domestication  of  Animals.     Scientific  American,  .Iatniar\-  10,  l\tl\. 

Schaler,  Domesticated  Animals,  Their  Relations  to  Man  and  tu  Ilia  Adcanccmcnt  in 

Civilization.     Charles  Scribner's  Sons. 
vScudder,  Guide  to  the  Common  Bnttcrflies.     Henry  Holt,  and  Company. 
Seton,  Wild  Animals  I  Hare  I\.nown.     Charles  Sfribner's  Sons. 
Shipley,  Honeybee.     Edinburgh  licincw,  .January,  1!)I1. 
Stone  and  Cram,  American  Animals.     Doubleduy,  Page  and  Conipauy. 
Wright,  Four-footed  Americans.     The  Macmillan  Company. 


HUNTER   LAB.    PROB.  —  10 


XV.  THE  ECONOMIC  IMPORTANCE  OF  ANIMALS 

Problems.  —  I.  To  determine  the  uses  of  animals. 

(a)  Ijidirectly  as  food. 

{h)   Directly  as  food. 

(c)   As  domesticated  animals. 

id)  For  clothing. 

(e)   Other  direct  economic  uses. 

(/)  Destruction  ofharnifivl  plants  and  animals. 

II.  To  determine  the  harm  done  hy  animals. 

(a)  Animals  destructive  to  those  used  for  food. 

(Jb)   Animals  harmful  to  crops  and  gardens. 

(c)   Animals  harmful  to  fruit  and  forest  trees. 

id)  Animals  destructive  to  stored  food  or  clothing. 

(e)   Animals  indirectly  or  directly  responsible  for  disease. 

To  THE  Teacher.  —  Inasmuch  as  this  work  is  planned  for  the  winter  months 
the  laboratory  side  must  be  largelj'  museum  and  reference  work.  It  is  to  be  ex- 
pected that  the  teacher  will  wish  to  refer  to  much  of  this  work  at  the  time  work  is 
done  on  a  given  group.  But  it  is  pedagogically  desirable  that  the  work  as  planned 
should  be  varied.  Interest  is  thus  held.  Outlines  prepared  by  the  teacher  to  be 
filled  in  by  the  student  are  desirable  because  they  lead  the  pupil  to  individual  selec- 
tion of  what  seems  to  him  as  important  material.  Opportunity  should  be  given 
for  laboratory  exercises  based  on  original  sources.  The  pupils  should  be  made  to 
use  reports  of  the  U.  S.  Department  of  Agriculture,  the  Biological  Survey,  various 
state  reports,  and  others. 

Special  home  laboratory  reports  may  be  well  made  at  this  time,  for  example : 
determination  at  a  local  fish  market  of  the  fish  that  are  cheap  and  fresh  at  a  given 
time.  Have  the  students  give  reasons  for  this.  Study  conditions  in  the  meat 
market  in  a  similar  manner.  Other  local  food  conditions  may  also  be  studied  first 
hand. 

This  chapter  is  intended  to  be  a  practical  resume  of  the  use  and  harm  done 
by  animals.  Some  of  the  work  is  intended  as  a  change  from  pure  laboratory  work 
to  that  of  reference  reading.  But  some  extremely  important  work  outlined  in  this 
chapter  should  be  taken  when  the  season  will  allow,  in  the  laboratory,  in  the  field, 
or  at  home.  Practical  work  on  the  relation  of  mosquitoes  and  flies  to  disease  should 
be  part  of  every  educated  person's  knowledge,  for  ability  to  deal  with  these  pests 
may  mean  health  as  well  as  comfort  in  the  home  locality. 

146 


PROBLEM    119 


117 


Problem    119:  What    animal  foods    arc   chcapcfit    in    any 
locality  and  wliy?    (Home  work.) 

Method  and  Observations.  —  a.  Visit  your  local  fish  and  moat 
markets.  If  in  New  York,  read  the  publications  of  tlie  Mayor's 
Food  Supply  Committee.     Make  tables  of  the  fish  and  meats  that 


Name  of  Fish 

Habitat 

Price  for 
lb. 

Kexnarks 

1. 

2,. 

etc. 

1 

o/Mecl 

Anin»nl  it 

ComM  jrom 

Habitnl 

Ot.t  .r 
l*urt  Eat«n 

)..r  lU 

R*Kark< 

are  relatively  cheap  and  those  that  are  expensive.  Go  to  the  li- 
brary and  look  up  in  an  encyclopedia  or  Jordan  and  Evermann's 
American  Food  and  Game  Fishes  the  habitat  of  each  fish  you  have 
priced.  In  Hornaday's  American  Natural  History  or  an  ency- 
clopedia look  up  the  habitat  of  the  animals  which  supply  the 
meats  you  have  priced.  Read  Kipling's  Captains  Courageous  to 
see  how  certain  fish  are  ^_-^ 

obtained. 

h.  Using  the  figure, 
locate  the  various  cuts 
of  meat  priced  at  the 
market.  You  will  find 
that  the  cut  of  meat 
(part  of  animal  used) 
determines  the  price, 
and  this  price  is  further 
determined  b}^  the  de-  ^  .'-.- 

mand  of  people  buying  and  the  sui:)ply  in  the  market. 

Conclusion.  —  1.    Does  the   habitat  of  the   animal   have  any- 
thing to  do  with  it^  price  in  the  market? 

2.  What  other  factors  might  infiuence  the  price  uf  fish?     Ask 
your  teacher  to  help  you  in  this. 

3.  What  factors  might  determine  the  price  of  meat  ? 

4.  What  factors  largely  determine  the  price  oi  cut.><  of  meat? 


, . — ;'?K?.''»iPT^r^"-j.r5iow. 


»Wi-.rj:,77^ 


148    THE   ECONOMIC   IMPORTANCE   OF  ANIMALS 


Hnbitat 

T/se    of 
Products 

Preparat  iorv 
oj  Products 

OtKe-r 

Fatts 

Problem  I'^O:  How  animals  may  benefit  mankind. 
Materials.  — Hunter's  Civic  Biology,  pages  197-231,  Toothaker's 
Commercial  Raw  Materials,  Government  and  State  Department  re- 
ports of  various  kinds. 
A  visit  to  a  commercial 
museum. 

Method.  —  Using 
your  sources  of  in- 
formation, make  out 
in  tabular  form  a  report  giving  (1)  habitat,  (2)  use,  (3)  prep- 
aration of  product,  (4)  other  interesting  facts  with  reference 
to  the  following  animals:  cow,  sheep,  horse,  pig,  whale, 
walrus,  honeybee, 
ichneumon  fly,  silk- 
worm, ladybug,  tach- 
ina  fly,  gall  insects, 
blister  beetles,  lac  in- 
sect, cochineal,  bum- 
blebee, carrion  beetle, 
toad,  house  wren, 
cuckoo,  bank  swallow, 
bluebird,  woodpecker, 
brown  thrush,  guH, 
vulture,  owl,  black 
snake,  milk  snake, 
green  snake. 

Conclusion.  —  In 
what  ways  are  the 
above  animals  useful 
to  man? 

Problem  121:    To 

find  out  how  birds 
are  of  economic  im- 
portance. 

Materials.  —  Pam- 
phlets of  the  Depart- 


V). 

T3 

o 

Bobolink 

Blackbird 

Ccjtbird 

Coopers  Hawk 

Cro'^^^' 

Ct4  ckoo 

D  ove 

En  glisli  Sparrow 

a  VI 11 

Kiivgbird 

Kingj"i$Ker 

Ow^l,  Horned 

PKoebe 

Qwail 

Robiix 

Say  s  ucker 

Starling 

Swallow 

ThrusK 

V7"T«e.Tv. 

PROIM.EM   12:] 


149 


ment  of  Agriculture  (see  list  of  Reference  Books)  and  Civic  Biohxjij, 
pages  209-211. 

Method  and  Observations.  —  I'ill  oul  Uk^  i)i('c('(liiig  tahlc 
on  the  food  of  some  birds,  using  references  suggested  above. 

Conclusion.  —  Which  of  the  birds  are  of  use  to  man  ?  ( )f  harm  ? 
Which  may  be  of  both  harm  and  use?     Explain  yom-  answers. 

Problem  122:  What  are  the  causes  of  decrease  in  tlie 
nuiJiher  of  birds  ? 

Method  and  Observations. 
• — Using  your  own  experience 
and  the  information  obtained 
from  Hornaday's  Our  Van- 
ishing Wild  Life,  complete  a 
table  like  the  accompanying. 

Conclusion.  —  In  a  care- 
fully written  paragraph  sug- 
gest some  methods  of  prevent- 
ing the  decrease  of  our  helpful 
birds. 

Problem  123 :  To  study  the  life  history  of  the  mosquito. 

Note.  —  There  are  four  distinct  stages  in  the  devclopinont  of  the  mosquito: 
egg,  larva,  pupa,  and  adult.     These  will  be  taken  up  and  studied  in  order. 

a.  The  Egg 

Method.  —  The  eggs  of  mosquitoes  are  laid  on  the  surface  of  still 
salt  or  fresh  water  pools  from  April  to  October.     By  placing  a 

can  of  water  in  a  lot,  we  can 
often  obtain  the  small  rafts 
of  eggs  of  the  connnon  mos- 
quito, the  culex,  and  less  often 
the  single  floating  eggs  of  the 
malarial  mosquito,  the  anopheles.  Any  standing  water,  especially  in 
barrels,  old  cans,  neglected  drains,  catch  basins,  and  swamps,  may 
make  a  near-by  neighborhood  almost  uninhabitable.  The  yellow- 
fever  mosquito,  stegomyia,  is  not  found  in  the  North  but  is  found 
in  the  warmer  parts  of  the  United  States. 


Factors 

Birds 
A/fected 

H  0  v.^ 
Affected 

R^fnedie* 
Propofoci 

Clearing  0/  Forvjis 

Tultivution  ofhand 

SlauahtfT  fordame 

for  Feat  hors 

EggColI«>rtii\g 

Use  as  Food 

Cctts.V/easels, 

Sparrows  ,Jny»,ete 

V 
'^^^^^> 

K 


150    THE   ECONOMIC   IMPORTANCE   OF  ANIMALS 

b.  The  Larva    (Wiggler) 

Materials.  —  The  eggs  will  hatch  if  kept  in  a  warm  place,  or 
wigglers  can  be  scooped  from  a  pond  or  pool  of  water.  These 
may  be  kept  in  a  screened  battery  jar  half  full  of  water. 

Observations.  —  What  is  the  shape  of    the  larva3?     How   do 

they  move  through 
the  water?  Watch 
the  larvae  while  at  the 
surface.  Which  end 
is  up?  (Note  the 
breathing  tube  that 
reaches  through  the 
surface  of  the  water.)  What  is  the  position  of  the  larvae  while 
at  the  surface?  If  they  lie  horizontal  to  the  surface,  they  are 
the  larvae  of  the  ano'pheles,  the  malarial  mosquito ;  if  at  an  acute 
angle,  the  larvae  are  those  of  culex,  the  harmless  mosquito. 

c.  The  Pupa 

Method  and  Observations.  —  Place  a  number  of  wigglers  in  a 
screened  battery  jar.  Allow  them  to  cast  off  their  skins  and 
become  pupae.  How  does 
this  stage  differ  from  the 
larval  stage?  Notice  the 
empty  shells  of  the  pupae 
floating  on  the  surface  of 
the  water.  How  did  the 
adult  mosquitoes  get  out? 
Do  the  pupae  come  to  the  surface  of  the  water?  If  so,  why? 
Compare  the  position  of  the  pupae  at  rest  with  the  figures.  Is 
the  mosquito  a  culex  or  an  anopheles  ? 


d.  The  Adult 

Observations.  —  In  a  hatched  adult  observe  the  number  and 
kind  of  wings.  In  which  insect  group  do  mosquitoes  belong? 
Notice  the   antennae   or  feelers.     (The  males  have  more  bushy 


PROBLEM    125 


151 


feelers.  Males  do  not  bite.)  What  is  the  restinj^  position  of  the 
adult?  Compare  with  the  figures  on  page  218,  Civic  BioUnjij,  and 
decide  what  kind  of  mosquito  it  is. 


Conclusion.  —  Write  in  a  concise  paragraph  a  short  life  history 
of  the  mosquito,  either  culex  or  anopheles. 

Prohleni  124:  To  find  tlw  hreedi]i^  ])Jaces  of  Dinsqititoes  in 
any  locality  and  how  to  destroy  tJiem. 

Field  Trip.  —  Plot  a  map  of  your  (Ustrict  showing  all  tin*  water 
that  might  contain  mosquito  larvifi.  Remember  that  tin  cans  in 
rubbish  heaps,  flat  tin  roofs  or  gutters,  anything  that  can  hold 
water  for  two  weeks  at  a  time  may  breed  mosquitoes.  Look  (•ar(^- 
fully  for  larvae  or  pupffi.  (^n  the  map  note  with  a  cro.ss  where 
you  have  found  them.  If  such  localities  are  found,  go  to  the 
householder  and  explain  what  you  have  found. 

Conclusion.  —  If  mosquitoes  can  fly  several  hundred  yaitls  from 
their  l^reeding  places,  is  my  liotno  snfe  from  mosquitoes? 

ProhU'in  I2r>:  To  dctcriniuc  sontr  nirfhoils  of  destroying 
mo^qnitoes. 

Materials.  —  Mosquito  l;irv;r  mfkI  |)iip:i'.  b.il  1(M\'  j;ir.  kerosene 
oil,  goldfish. 


152    THE   ECONOMIC   IMPORTANCE   OF   ANIMALS 

Method  1.  —  Put  a  few  mosquito  larvae  and  pupae  in  a  small 
battery  jar.     Pour  in  a  few  drops  of  kerosene  oil. 

Observations.  —  What  happens  to  the  oil  and  the  water  ? 
What  becomes  of  the  larvae  and  pupae  ?  Remembering  that  all 
eggs  are  laid  on  the  surface  of  the  water,  what  would  happen  to  the 
eggs  when  laid? 

Method  2.  —  Place  some  small  goldfish  or  sticklebacks  in  a  jar 
containing  larvae  and  pupae. 

Observations.  —  What  happens? 

Conclusion.  —  Now  go  over  the  map  you  have  made.  Which 
of  the  above  means  would  you  use  to  exterminate  mosquitoes  in 
your  locality? 

Prohlein  126 :  To  find  the  relation  of  mosquitoes  to  diseases 
of  man. 

Note.  —  Malaria  and  yellow  fever,  diseases  caused  by  tiny  protozoans,  are 
transmitted  to  man  through  the  bite  of  mosquitoes.  This  is  proved  because  men 
have  escaped  malaria  in  malaria-infected  districts  by  taking  precautions  to  have 
their  bodies  at  all  times  protected  from  the  bite  of  the  mosquito.  This  was  done 
by  screening,  by  remaining  indoors  at  times  when  the  mosquitoes  were  out,  and  by 
wearing,  when  exposed,  head  nets  and  gloves. 

In  1890  two  London  doctors  allowed  themselves  to  be  bitten  by  anopheles  mos- 
quitoes which  had  previously  bitten  people  who  had  malaria.  In  a  little  over  two 
weeks  both  came  down  with  malaria. 

Observations. — What  causes  malaria?  What  have  swamps 
and  stagnant  water  to  do  with  malaria?  Why  did  the  people 
who  were  screened  not  get  malaria  ?  Why  did  the  London  doctors 
get  malaria? 

Conclusion.  —  What  has  the  anopheles  mosquito  to  do  with 
malaria  ? 

Problem  127 :  To  study  the  life  history  of  the  parasite  caus- 
ing malaria. 

Material.  —  Charts,  or  illustration  in  Hunter's  Civic  Biology, 
page  217. 

Observations.  —  Note  the  lower  part  of  the  diagram  which 
represents  the  blood  tube  of  a  man.  What  changes  take  place  in 
the  parasite  within  the  corpuscles?  What  two  kinds  of  organisms 
ultimately  are  formed? 


PROBLEM    128 


153 


zjever  sta^^ 


Notice  that  the  malarial  parasite  passes  part  of  its  life  history  in  the  body  of  the 
mosquito,  and  part  in  the  human  body.  The  lower  part  of  the  figiire  rojire- 
sents  a  blood  vessel  in  man.  The  parasites  live  part  of  their  lives  in  the  blood 
corpuscles.  Then  they  multiply  and  break  out  of  the  corpuscles.  (See  right 
side  of  figure.)  Using  this  figure  and  information  from  your  Civic  Biology, 
work  out  the  complete  life  history  of  the  malarial  parasite. 

What  happens  if  these  organisms  are  taken  into  the  mosquito's 
body  ? 

Note.  —  Only  when  both  forms  of  cells  are  taken  into  the  body  of  the  mo.squitt) 
arc  the  parasites  able  to  continue  their  development  there. 

Conclusion.  —  How  might  malaria  be  transmitted? 

JProblem  128 :  To  study  tlie  life  history  of  the  typhoid  jly. 

Materials.  —  Raw  meat,  glass  chshes. 

Method.  —  Expose  pieces  of  raw  beef  where  flies  will  light  on 
them.  After  a  few  hours  eovei*  in  glass  dishes  or  small  hatlery 
jars  with  screen  covers. 

Observations.  —  Watch  the  meat.  In  pieces  on  which  eggs  wtM'c 
laid  by  the  fiies  describe  the  stages  of  development  as  they  appear. 
Do  the  larvae  grow  any?     They  are  called  fnn(j(jols.     ITow  do  the 


154     THE  ECONOMIC   IMPORTANCE   OF   ANIMALS 

pupae  differ  from  the  larvae?     Watch  to  see  the  adults  emerge 
from  the  pupal  case.     How  long  does  a  complete  life  history  take  ? 
Conclusion.  —  How  many   generations   of   flies  might  develop 
during  a  hot  summer? 

Problem  129 :  To  determ-ine  the  harm  done  by  the  fly  and 
the  way  it  does  this  harin. 

Material.  —  Sterile   Petri   dish   containing   culture   medium. 

Method.  —  Allow  a  fly  to  walk  over  the  surface  of  a  sterile 
Petri  dish  with  culture  medium  within  it.  Cover  the  dish.  After 
three  or  four  days  examine  the  surface  of  the  culture  medium. 

Observations  —  What  do  you  see? 

Note.  —  Flies  breed  in  manure,  filth  of  all  kinds,  and  human  excrement  as  well. 

Study  a  diagram  showing  the  relation  of  typhoid  fever  to  open 
toilets  and  flies  in  Jacksonville,  Fla.  (page  224,  Civic  Biology). 
Why  were  there  fewer  cases  when  the  toilets  were  screened  ? 

Study  the  diagram  below.  What  relation  exists  between 
diarrheal  diseases  and  flies?     Explain. 

Examine  the  foot  of  a  fly  under  the  compound  microscope  or 
study  upper  figure,  page  223,  Civic  Biology.  What  adaptations 
for  carrying  germs  do  you  find? 


Infant  Mortality  Curve. 

a,  prevalence  of  flies ;    b,  diarrheal  under  five  years ;   c,  deaths  under  one  year ; 

d,  mean  temperature. 


PROBLKAI    131 


155 


Conclusion.  —  1.    What  diseases  may  be  carried  l)y  flies?. 

2.  Where  do  they  j;-et  the  germs  of  these  diseases? 

3.  How  do  they  carry  these  (hseases? 

Problem  i:u>:  IJluU  is  the  best  way  f<»  cat  eh  and  destrmj 
flies?     (Homework.) 

Materials.  —  Flytrap,  tin  plate,  carbolic  acid,  and  in.sect  powder. 

Method  and  Observations.  —  Make  a  flytrap  acconhn*!;  to  tlie 
plan  shown ;  bait  it  with  stale  fish  or  other  fo(xl.  Leave  it  for  one 
day,  then  plunge  it  into 
boiling  water  and  count 
the  number  of  flies 
which  you  caught. 

Heat  a  tin  plate 
containing  strong  car- 
bolic acid  so  that  the 
fumes  will  fill  a  room 
{e.g.,  the  kitchen)  con- 
taining a  number  of 
flies.  What  results  ? 
How  does  it  compare 
with  your  trap  ? 

Burn  a  few  ounces 
of  insect  powder  in  a  pan  in  the  same  room  on  another  day. 
Compare  your  results  with  those  above. 

Conclusion.  —  1.  Which  is  the  best  method  of  those  given  for 
destroying  flies  in  your  home  ? 

2.  Knowing  when  and  where  flies  breed,  when  would  be  the 
best  time  to  '^  swat  the  fly"?  How  would  this  nietliod  com- 
pare with  other  ways  of  extermination  studied? 


An  easily  made  Flytrap. 


Problem  131 :  To  deterviine  harm  done  by  insects. 

Materials.  —  Trips  to  museum,  reference  to  texts,  and  various 
bulletins  of  the  Department  of  Agriculture. 

Observations.  —  Make  out  in  the  form  of  the  following  table  a 
report  on  the  harm  done  by  insects  : 


156    THE   ECONOMIC   IMPORTANCE  OF   ANIMALS 


Ncinve 

Harm  done. 

Sta  cse'wXen 
it  does  horm 

the  pest 

1.  To  gardens.  —  Report  on  cutworm,  corn  worm,  potato 
beetle,  squash  bug. 

2.  To  crops.  —  Boll  weevil,  chinch  bug,  plant  lice,  Hessian  fly. 

3.  To   fruit   and   forest  trees.  —  Codling  moth,  gypsy   moth, 

tussock  moth,  hickory 
borer,  maple  borer, 
scale  insect. 

4.  To  stored   food. 
— Weevils,  roach,  ant. 

5.  To  clothes,    etc. 
— Clothes  moth,  roach. 

6.    As  disease  carriers.  —  Flies,  mosquitoes,  fleas,  bedbugs. 

Report,  using  the  above  sources  of  information,  on  specific 
ways  of  combating  one  pest  from  each  of  the  above  groups. 

Conclusion.  —  What  specific  harm  is  done  by  the  above-named 
insects  and  how  would  you  go  to  work  to  prevent  this  harm  ? 

JProbletn  Vi2 :  To  hnow  some  forjns  of  animal  life  that  cause 
disease. 

Materials.  —  Use    your    Civic    Biology,    Chap.    XV,    or    any 
other  source  of  infor- 
mation. 

Observations.  — 
Fill  in  the  accompany- 
ing chart,  giving  infor- 
mation with  refer- 
ence to  disease-caus- 
ing animals,  especially 
hookworm,  tricliina, 
and  tapeworm. 

Conclusion.  —  1. 
What  animals  cause 
disease  and  what  dis- 
eases do  they  cause? 

2.  How  would  you 
attempt  to  cure  anj^  three  of  these  diseases? 

3 .  How  would  you  attempt  to  prevent  any  three  of  these  diseases  ? 


Name  of 
Disease 

J>iSease 

Caused  by 

Diseose 

Carried  by 

How  to  /itf^t 

tWtofi*]<t 
Carrie  n 

Bubonic  Plague 

Hookv/orm 

Kala:A3flr 

Leprosv- 

Mdlciria: 

Rdloi  e  s 

Sleeping  Sickness 

Snv«n    Pox 

Xci  p  e.'v^o  r  itv 

Teiccts  Fever 

TricKmosls 

T^pKold 

IfellowFevep 

REFERENCE  BOOKS  i; 


)/ 


Problem   Questions 

1.  How  long  does  it  take  for  one  generation  of  flies  to  develop? 

2.  During  what  part  of  the  year  are  flies  most  abundant  ?    Wliy  ? 

3.  During  the  Spanish-American  War  flics  were  more  deadly 
than  Spanish  bullets.     Explain. 

4.  What  diseases  may  be  carried  by  flies? 

5.  What  relation  has  the  garbage  pail  to  the  tyi^hoid  fly?     Ex- 
plain. 

6.  Why  should  food  exposed  for  pul^lic  sale  i)e  kept  covered? 

7.  Why  should  food  on  the  table  be  screened? 

8.  What  dangers  come  from  open  spittoons  and  what  do  flies 
have  to  do  with  this  danger? 

9.  Why   should   garbage   pails   be   frequently   sprinkled    with 
slaked  lime  or  kerosene? 

10.  Why  the  cry  in  the  early  spring  —  ''  Swat  the  fly  ''  ? 

11.  What  harm   do   mosquitoes   do?     How   do   they   do   this 
harm  ? 

12.  What  are  the  natural  enemies  of  the  mosquito? 

13.  How  would  you  go  to  work  to  rid  your  neighborhood  of 
mosquitoes  ? 

14.  How  would  you  tell  harmful  from  harmless  mosquitoes? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XV.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chap.  XIX.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XVII.     American  Book  Conipany. 

Bigelow,  Visiting  a  Fish  Hatchery.     Guide  to  Nature,  Decern  I  )cr,  19()S. 

Britton,  Mosquito  Plague  of  Connecticut  Coast  Region.     Connei-ticut  ARricultural 

Experiment  Station. 
Burroughs,  Squirrels  and  Other  Fur  Bearers.      Iloughton.  MifUiii  Company. 
Carter,  The  Vampire  of  the  South.     McClurc's  Magazine,  October,  1900. 
Chappell,  The  House  Fly  —  Alan  Killer.     Pearsou'-s  Magazine,  .lunc.  1910. 
Daugherty,  Economic  Zoology.     \\ .  li.  Saun(l«M-s. 

Davenport,  Introduction  to  Zoology,  pp.  1.^1-158.     The  iMacnjilhin  Company. 
Doane,  Insects  and  Disease.     Henry  Holt  and  Company. 
Dotey,  The  Mosquito.      N.  Y.  State  Journal  of  Medicine.  19()S. 
Felt,  Insects  Injurious  to  Forest  Trees.      New  York  State  Ueport-s,  1S9S. 
Field,  .Sea  Mussels  as  Food.      Bureau  of  Fisheries  DocunuMit,  1910. 
Forbes,  The  Lake  as  a  Microcosm.      Bulletin.  Peoria  (III.)  Science  .\.s.sociation.  1SS7. 
Frost  and  Voorhees,  The  House  Fly  Xuisance.     Country  Life  in  America,  May.  190S. 


158     THE   ECONOMIC   IMPORTANCE  OF  ANIMALS 

Hatch,  The  Indictment  of  the  House  Fly.     Suburban  Life,  March,  1910. 

Hayncs,  Mad  Dog.     Country  Life,  July,  1914. 

Herrick,  Textbook  in  General  Zoology,  Chap.  VIII.     American  Book  Company. 

Hodge,  Nature  Study  and  Life,  Chap.  XVI.     Ginn  and  Company. 

Howard,  The  House  Fly,  Disease  Carrier.     F.  A.  Stokes  Company. 

Howard,  The  Typhoid  Fly.     Bulletin  78,  Bureau  of  Entomology,  U.  S.  Department 

of  Agriculture. 
Howard  and  Marlatt,  Principal  Household  Insects  of  the  United  States.     Bulletin 

4,  U.  S.  Bureau  of  Entomology,  1902. 
Huber,   Insects  and  Disease.     New   York  State  Journal  of  Medicine,   November, 

1908. 
Insects  —  pamphlets.  Bureau  of  Entomology,  158  ;    Farmers'  Bulletin,  155. 
Jordan,  Fishes.     Henry  Holt  and  Company. 

Jordan  and  Kellogg,  Animal  Life,  Chaps.  X-XI.     D.  Appleton  and  Company. 
Kellogg,  Shellfish  Industries.     Henry  Holt  and  Company. 
Kellogg,  Elementary  Zoology,  pp.  297-298.     Henry  Holt  and  CompanJ^ 
Kellogg  and  Doane,  Economic  Zoology  and  Entomology.     Henry  Holt  and  Company. 
Kinyoun,    Uncinariasis    in    Florida.     Report    of    American    Health    Association, 

1907. 
Langworthy  and  Hunt,  Economical  Use  of  Meats  in  the  Home.     Bulletin  391,  U.  S. 

Department  of  Agriculture,  1910. 
McGuire,  The  Hookworm  and  the  South.     Pearson's  Magazine,  September,  1909. 
Medical  Influence  of  the  Negro  in  Connection  with  Anaemia  in  the  White.    Bulletin 

North  Carolina  Board  of  Health,  June,  1908. 
Osborn,  Economic  Zoology,  Chaps.  IV-V.     The  Macmillan  Company. 
Ransom,  Trichinosis :    a  Danger  in  the  Use  of  Raw  Pork  for  Food.     Circular  198, 

U.  S.  Department  of  Agriculture,  1907. 
Seymour,  War  on  Agricultural  Pests.     World's  Work,  May,  1914. 
Smith,  The  French  Sardine  Industry.     Bulletin  U.  S.  Fish  Commission,  1901. 
Smith,  Uncinariasis  (Hookworm)  in  Texas.     American  Journal  of  Medical  Science, 

1903. 
Soil  Pollution  and  the  Hookworm  in  the  South.     Alabama  Board  of  Health. 
Spangler,  The  Decrease  of  Food  Fishes  in  American  Waters,  and  Some  of  the  Causes. 

Bulletin  U.  S.  Fish  Commission,  1893. 
Stevenson,  Preservation  of  the  Fisheries  on  the  High  Seas.     Popular  Science  Monthly, 

April,  1910. 
The  Coming  War  on  the  Hookworm.     Current  Literature,  December,  1909. 
Thompson,  The  Study  of  Animal  Life,  Chap.  IV-V.     Charles  Scribner's  Sons. 
Webster,  The  Value  of  Insect  Parasitism  to  the  American  Farmer.     Yearbook  U.  S. 

Department  of  Agriculture,  1907. 
Wieland,  Conservation  of  the  Marine  Vertebrates.     Popular  Science  Monthly,  May, 

1908. 


XVI.  THE  FISH  AND  FROG,  AN  INTRODrCTORY 

STUDY  OF  VERTEBRATi:s 

rt'ohlemfi.  —  To  determine  how  a  fish  and  afvo^  are  fitted  for 
the  life  tliey  lead. 

To  determine  some  methods  of  development  in  vertebrate 
animals. 

(a)  Fislxes. 

(b)  Frogs. 

(c)  Other  animals. 

Laboratory  Suggestions 

Laboratory  exercise.  —  Study  of  a  living  fish  —  adaptations  for  protec- 
tion, locomotion,  food  getting,  etc. 

Laboratory  demonstration.  —  The  development  of  the  fish  or   frog  egg. 

Visit  to  the  aquarium.  —  Study  of  adaptations,  economic  uses  of  fishes, 
artificial  propagation  of  fishes. 

To  THE  Teacher.  —  This  chapter  is  intended  to  introduce  the  student  to  the 
life  history,  structure,  and  adaptations  found  in  a  vertebrate,  the  fish  or  frog.  If 
time  permits,  both  forms  may  be  used,  but  the  writer  has  found  that  f(jr  use  in  the 
early  spring  (which  would  be  the  logical  time  for  this  exercise  if  the  course  was  lie- 
gun  in  the  fall)  the  frog  is  a  more  useful  form  because  of  its  superficial  similarity  to 
the  structure  of  man  and  because  of  the  ease  with  which  developmental  material 
may  be  obtained. 

The  fish,  however,  as  a  living  specimen  for  laboratory  use  is  excellent,  espe- 
cially for  the  study  of  adaptations.  The  concept  of  a  structural  adaptation  is  ex- 
tremely difficult  for  a  pupil  beginning,  and  considerable  drill  should  be  given  in  an 
attempt  to  fasten  the  concept.  Field  or  acjuarium  trips  may  Ix?  made  to  form  an 
important  part  of  this  work,  thus  adding  interest  through  varied  work. 

Problem  133 :  To  determine  how  alive  fish  is  fitted  for  life. 
Materials.  —  Small  battery  jar  with  small  living  lish  such  as 
goldfish,  bream,  or  minnows. 

a.  Locomotion 
Observations.  —  Note  adaptations  for  locomotion.     How  is  the 
body  of  the  fish  fitted  for  life  in  the  water?     Mention  three  dif- 

159 


160  THE  FISH   AND   FROG 

ferent  adaptations.  Watch  the  fish  carefully  and  locate  its  organs 
for  movoment.  How  many  single  fins  are  there?  How  many 
paired  fins? 

NOTE.  —  Fins  on  the  upper  side  of  the  body  are  called  dorsal  fins,  the  tail  fin 
is  called  the  caudal  fin,  and  the  single  fin  on  the  lower  side  is  the  anal  fin.  The  front 
paired  fins  are  called  the  pectoral  fins,  while  those  just  below  and  behind  are  called 
the  pelvic  fins. 

Try  to  discover  the  use  in  movement  of  each  of  the  above- 
named  fins. 

Conclusion.  —  1.  How  does  a  fish  move?  Watch  the  fish 
swimming  and  try  to  decide  what  fins  are  used  in  moving  forward, 
in  turning,  in  moving  backwards.  Note  whether  the  body  is  used 
in  locomotion. 

2.  Tell  just  how  any  particular  fin  is  adapted  or  fitted  to  do  its 
work.  (Remember  you  must  show  how  a  structure  is  especially 
designed  to  do  a  particular  work.) 

3.  How  is  the  body  fitted  for  life  in  the  water? 

b.  Protection 

Method.  —  Examine  carefully  a  preserved  specimen. 

Observations.  —  What  structures  do  you  find  on  the  surface  of 
the  body?  How  are  these  structures  placed  with  reference  to 
each  other?  Feel  the  body  of  the  fish.  What  adaptation  for 
protection  exists  here?  Note  the  color  both  above  and  below. 
Remembering  that  many  of  the  enemies  of  the  fish  are  below  him 
and  some  above,  explain  how  the  animal  receives  protection  from  its 
color. 

Conclusion.  —  What  are  the  principal  adaptations  for  protec- 
tion in  the  fish  ? 

c.  Breathing 

Method.  —  Look  at  the  fish  carefully  and  observe  the  move- 
ments of  the  mouth. 

Observations.  —  What  is  the  relation  of  the  movement  of  the 
mouth  to  that  of  the  operculum,  the  flap  which  covers  the  gills? 
Note  position  and  color  of  the  gills.  What  gives  them  this  color? 
Introduce  "  few  grains  of  carmine  in  the  water  in  front  of  the 
mouth  of  the  fish.     Trace  the  course  of  the  carmine.     Where  does  it 


PROBLEM   11^6  h;1 

come  out?     What  gas  is  in  tho  water?     How  !iii^r},j   jl„.  fish  use 
this  gas?     How  might  this  gas  come  ifi  conlacl  with  ihc  gills? 

Conclusion.  —  Tell  just  how  a  fish  hn^athes,  writing  a  i)aragraph 
in  explanation  and  illustrating  with  a  diagram. 

Troble^n  134 :  To  study  food  getting  bjj  the  fish. 

Material.  —  Live  fish. 

Method.  —  Watch  the  fish  to  see  if  it  will  eat.  Ilememher 
what  you  know  about  catching  fish. 

Observations.  —  Do  fish  see  or  are  they  made  aware  of  the 
presence  of  food  by  other  means?  Do  fish  have  teeth?  Do  they 
chew  their  food?  Give  uses  of  teeth.  How  does  the  fish's  means 
of  obtaining  food  compare  with  ours  ? 

Conclusion.  —  Write  a  paragraph  telhng  how  a  fish  gets  its 
food. 

Prohle^n  13^ :  To  study  the  sense  organs  of  tlie  fish. 

Material.  —  Specimens  of  fish. 

Method.  —  Study  the  external  sense  organs  of  the  fish.  \\  hat 
are  they? 

Observations.  — What  shape  are  the  eyes?  Does  a  fish  move 
its  eyes?  Describe  any  movement.  A  fish  is  very  nearsighted 
owing  to  the  shape  of  the  eye.  Find  two  nostril  holes.  These 
lead  to  little  pits  in  which  are  located  the  nerves  of  smell.  Does 
a  fish  breathe  through  its  nose?  Find  a  distinct  line  running  down 
the  side  of  the  fish.  This  is  called  the  lateral  line  and  contains 
organs  of  sense.  The  ears  of  the  fish  are  out  of  sight  in  the  lu-id 
and  are  largely  used  for  balancing. 

Conclusion. — Write  a  paragraph  telling  how  llu*  fish  is  fitted 
with  sense  organs.  Compare  its  vision,  sense  of  smell,  and  power 
of  lu^aring  with  your  own  in  respect  to  keenn(\ss. 

Drawing.  —  Make  a  side  view  of  a  fish.  Label  all  the  struc- 
tures we  have  discussed. 

rrohlem  J  30  :  To  study  some  of  the  iuterual  organs  of  a  fish. 
Material.  —  Preserved    specimens   with    under   body    wall   cut 
away. 

HUNTER  LAB.   PROB.  —  11 


162  THE   FISH   AND   FROG 

Observations.  —  Push  a  blowpipe  down  the  gullet,  into  the 
baglike  stomach.  Then  follow  the  folded  intestine  until  it  reaches 
the  anus  or  vent,  where  the  solid  waste  leaves  the  body.  Find, 
partly  covering  the  stomach,  a  large  lobed  gland,  the  liver.  Just 
above  the  stomach  j^ou  will  find  the  ovary  or  spermary,  depending 
on  the  sex  of  fish  (female  or  male) .  Still  more  dorsal,  find  a  glisten- 
ing, thin-walled  sac,  filled  with  gases,  the  air  bladder.  Close  to  the 
backbone  will  be  found  the  dark  red  kidney.  Make  a  drawing  to 
show  all  of  these  organs  in  natural  position.  The  heart  is  found 
just  in  front  of  the  stomach.  Study  it  carefully,  comparing  it 
with  the  figure  on  page  235,  Civic  Biology.  Make  out  its  connec- 
tion with  the  gills,  the  red  structure  on  each  side  of  the  fish's 
head.  What  use  has  the  heart?  The  gills?  Why  should  blood 
be  sent  to  the  gills?  Study  a  chart  of  the  circulation  of  a  fish  to 
see  where  blood  comes  from  as  it  goes  to  the  heart  and  where  it 
goes  to  after  leaving  the  gills. 

The  complete  round  of  the  blood  from  the  heart  back  to  the  heart 
makes  up  the  circulation  of  blood  in  the  fish. 

Conclusion.  —  1.  What  are  the  various  systems  within  the  body 
cavity  of  the  fish  ? 

2.   What  do  you  understand  by  the  circulatory  system  ? 

Prohle^n  137 :  To  study  the  sheleton  and  central  nervous 
system  of  the  fish.    ( E  xtr a . ) 

Material.  —  Use  prepared  skeleton  or  chart. 

Observations.  —  Notice  the  column  of  bones  extending  from 
the  head  into  the  tail  of  the  fish.  This  is  called  the  vertebral  column^ 
or  backbone.  Of  what  advantage  to  the  fish  is  a  series  of  bones 
over  one  bone? 

Note.  —  The  central  nervous  system,  consisting  of  the  brain  and  spinal  cord, 
lies  inside  this  chain  of  bones.  To  this  central  sj^stem  nerves  pass  in  from  the  out- 
side of  the  body,  bringing  sensations,  while  other  nerves  pass  outward  to  muscles, 
causing  movement. 

Conclusion.  —  1.  What  are  the  uses  of  the  skeleton  to  the  fish? 

2.  W^hy  is  it  made  of  many  bones? 

3 .  Are  there  any  other  bones  in  the  fish  ?    Where  are  they  located  ? 

4.  How  is  the  nervous  system  protected? 


PROBLEM    189  103 

Problem  j:iS :  How  fishes  are  avtifirinlhj  jtrojia^atrd. 

Method.  —  The  operations  of  strippimj  can  lie  demonstrated 
in  the  classroom  at  certain  times  of  the  year,  oi-  if  tlic  school  is  in 
the  neighborhood  of  state  or  government  fish  hatcheries,'  visit 
them.  Make  careful  notes  on  the  artificial  methotls  of  raising 
fishes.  Observe  especially  the  equipment  of  the  hatchery  tanks, 
caretaking  of  fish,  etc.     (See  page  240,  Civic  Biology.) 

Observations.  —  Note  the  stripping  of  the  females  for  roe  (eggs) 
and  the  males  for  milt  (sperms).  Collect  and  examine  roe  and 
milt  under  the  compound  microscope.  Which  cells  are  larger, 
roe  or  milt?     Which  are  the  more  active?     Why? 

Why  are  the  eggs  squeezed  into  a  l)ucket  with  fresh  water 
and  the  milt  immediately  poured  over  them? 

Why  are  the  eggs  then  placed  in  receptacles  which  have  water 
running  through  them? 

NOTE.  —  Fresh-water  fishes  usually  lay  their  eggs  on  the  bottom  of  brooks  or 
rivers,  sometimes  in  nests  prepared  for  this  purpose.  After  the  eggs  are  laid  the 
male  sprays  them  with  milt. 

In  what  respects  does  artificial  fertilization  resem])le  this  process? 
Conclusion.  —  1.    Write  a  paragraph  on  the  process  of  artificial 
fertilization  in  fishes. 

2.  Which  would  be  a  surer  method  of  fertihzation,  artificial  or 
natural?     Explain. 

3.  Of  what  value  is  artificial  propagation  of  fishes? 

Problem  J39:  Trip  to  the  aquarium.  (Optional,  in  place  of 
Problems  133  and  138.) 

Method  and  Observations. —  Select  a  lively  fisli. 

Is  the  fish  protected  by  form  or  color?  If  so,  explain  how. 
Show  exactly  what  each  fin  does  for  the  fish  in  the  proce^^s  of  loco- 
motion. Can  a  fish  see?  Hear?  Smell?  (Jive  reasons  based 
on  your  observations.  Explain  exactly  how  a  fish  gets  its  oxygen 
in  breathing.     Make  a  diagram  in    your    nott^book  to  illustrate 

1  In  place  of  hatcheries,  study  figures  of  the  process,  for  salmon  or  (rouf.  See 
a  Manual  of  Fish  Culture,  Department  of  U.  S.  Fish  Commission  for  ISOS,  Plates 
16,  28,  34,  53,  especi  illy  for  salmon  and  trout. 


104 


THE   FISH    AND   FROG 


this.     Extra  credit  will  be  given  for  any  additional  observations 
to  show  how  the  fish  is  fitted  (adapted)  to  its  surroundings. 

Make  three  columns  on  your  paper.  Select  ten  fishes  of  eco- 
nomic importance.  Place  in  the  first  column  the  name  of  each 
fish,  in  the  second  its  habitat  (where  found),  in  the  third  its  use  to 
man. 


IMajwe   of   iP^xSlv 


HalDxt  cct 


Use    to  I^ctrv 


Write  a  paragraph  telling  how  these  different  fishes  actively 
protect  themselves  and  two  ways  in  which  fishes  are  protected. 
(By  being  like  their  surroundings  is  an  example  of  the  latter.) 
Give  the  name  of  the  fish,  and  its  habitat  in  each  case. 

Visit  a  hatchery  and  make  careful  notes  telling, 

(1)  The  method  of  fertilization  of  the  egg. 

(2)  The  kinds  of  eggs  that  are  hatching. 

(3)  The  apparatus  used  in  hatching  different  fish.  (Make  dia- 
grams to  illustrate.) 

(4)  Methods  of  caring  for  young  fish  after  they  are  hatched. 

(5)  Any  other  observations  on  the  process  and  its  general  use  to 
man. 

Conclusion. —  Write  up  your  trip  in  an  interesting  manner. 
Illustrate  it  if  possible,  and  hand  it  in  to  your  instructor  not  later 
than  two  daj^s  after  the  trip. 

Problem  140:  To  determine  some  adaptations  in  a  living 
frog. 

Materials.  —  Live  frogs,  battery  jars,  charts. 

Observations.  —  How  does  the  shape  of  the  frog  fit  it  for  life  in 
the  water?  Note  the  color  and  markings.  Feel  the  skin.  In 
what  respect  is  it  an  adaptation  ? 

Conclusion.  —  Remembering  where  a  frog  lives,  write  a  para- 
graph telling  how  the  frog  is  fitted  to  its  surroundings. 


PROBLEM    114  ]{]■) 

Problem  141:  Adaptations  ofaj)i)PH(la!^r<if<}r1()<'fmiofi(ni. 

Observations.  —  Locate  the  apixMidn^cs.  How  iiian\-  do  you 
find?  What  diti'erences  do  you  find  between  the  foic  and  liind 
legs?     What  purposes  do  the  hind  lep;s  serve?     'J'he  fore  legs? 

Conclusion.  —  1.  Show  exactly  how  the  h^gs  of  the  fr<jg  are 
fitted  for  locomotion. 

2.    Of  what  kind  of  locomotion  is  the  frog  capable? 

Problem  142:  Adaptations  for  sensation. 

Observations.  —  Touch  the  frog  gently  (if  possible  without  its 
seeing  you).  How  does  it  respond?  How  is  the  eye  fitted  for  its 
work  (position,  movement,  etc.)?  How  is  the  eye  protected? 
Touch  it.  Back  of  the  eye  find  the  eardrum.  Describe  il  in  size 
and  position. 

Conclusion.  — What  are  the  uses  of  each  of  the  sense  organs? 
Give  experimental  proof  if  possible. 

Problem  143:  Adaptations  for  food  getting. 

Method  and  Observations.  —  Open  the  mouth  of  a  freslily  killed 
frog  and  move  the  tongue.  Compare  with  figure  on  page  242, 
Civic  Biology.  Feel  both  jaws  to  find  whether  the  frog  has  teeth. 
Feel  the  roof  of  the  mouth. 

Conclusion.  —  Write  a  paragraph  telling  how  the  frog  uses  its 
tongue  and  teeth  in  catching  its  prey. 

Problein  144:  Adaptations  for  breathing. 

Method.  —  Watch  carefully  the  throat  and  sides  of  a  frog  that 
has  its  head  out  of  water.  Note  the  jndsations  of  the  throat. 
Count  the  number  of  movements  per  minute. 

Note  that  every  so  often  another  more  noticeable  movement 
occurs.  What  happens  to  the  nostril  holes  when  this  movement 
takes  place?  Does  this  latter  movement,  when  the  nostril  holes 
are  closed,  make  the  mouth  cavity  larger  or  smaller  ? 

Examine  a  dissected  specimen,  or  chart  showing  glottis, 
trachea,  bronchial  tube,  and  lungs.  Insert  a  blowpijx'  in  the 
glottis  and  inflate  the  lungs.     Are  they  clastic? 


166  THE  FISH  AND   FROG 

Conclusion.  —  1.  Where  must  the  air  go  when  the  frog  makes 
a  swallowing  movement  with  the   nostril  flaps   closed? 

2.  Write  a  paragraph  comparing  the  breathing  of  the  frog  and 
of  yourself. 

Drawing.  —  Draw  a  side  view  of  the  living  frog,  natural  posi- 
tion.    Label  all  parts  mentioned  in  the  previous  study. 

Problem  145 :  Museinn  trip  to  study  the  frog  group.  (Extra 
Problem  based  on  trip  to  American  Museum  of  Natural  History.) 

The  following  suggestions  might  be  modified  for  a  field  trip 
where  such  a  trip  is  possible. 

Method.  —  Begin  work  at  one  of  the  two  groups  on  which  ques- 
tions follow.  Read  the  labels  in  front  of  each  group  and  learn 
all  you  can  about  what  the  group  contains  before  you  begin  to 
answer  the  questions.  Then  answer  the  following  questions, 
making  the  answers  tell  a  connected  story  in  your  notebook.  Ask 
questions  of  your  teacher  only  when  you  cannot  find  the  answer 
to  a  question  yourself. 

a.  The  Toad  Group 

What  time  of  year  does  it  seem  to  be?  How  do  you  know? 
What  flowers  are  most  abundant  at  this  time  in  this  locality? 
(Ask  help  from  your  teacher  if  you  do  not  know  them.)  What 
animals  are  found  living  in  the  water?  On  the  land  or  in  the 
trees?  Both  on  land  and  in  the  water?  What  are  the  latter 
animals  called  ?     {Amphi  =  both.) 

Look  for  specimens  of  the  tree  frog  (hyla  diver sicolor) .  Describe 
three  different  changes  in  color  in  these  frogs.  In  what  ways 
are  these  changes  adaptations?     Explain. 

Describe  where  and  when  toads  lay  their  eggs.  Compare  the  egg 
masses  of  the  toad  with  those  of  the  frog.  How  are  the  eggs 
protected?  What  differences  can  you  find  between  toad  and 
frog  tadpoles ?     (Examine  preserved  specimens.) 

Enumerate  all  the  enemies  of  a  toad  seen  in  this  group  and  tell 
how  the  toad  is  fitted  (adapted)  to  escape  from  each  of  these 
enemies. 

Mention  three  structural  adaptations  found  in  a  toad  or  frog 


PROBLEM    116  167 

which  fit  it  for  the  life  it  leads.     Exi)lain  exactly  how  each  struc- 
ture you  have  described  is  an  adaptation. 

b.  The  Bullfrog  Group 

Show  three  ways  not  mentioned  in  tlu;  last  cjuestion  in  which  the 
bullfrog  is  fitted  or  adapted  to  its  environment.  At  what  time  r»f 
year  do  frogs  deposit  their  eggs  ?  How  does  it  compare  with 
that  of  the  toad?  (See  the  toad  group.)  How  do  you  account 
for  the  presence  of  the  large  tadpoles  found  swinuning  about? 

What  might  be  some  of  the  enemies  of  the  bullfrog  ?  How  might 
it  escape  from  its  enemies?  Explain  exactly  how  a  frog  catches  an 
insect.  Compare  the  habitat  of  the  bullfrog  with  other  ami)hib- 
ians  found  in  the  groups  in  this  alcove.  How  is  it  similar  and 
how  does  it  differ? 

Problem  146:  To  collect  and  study  frogs'  e£gs. 

Materials.  —  Trip  to  shallow  fresh-water  pond.  Battery  jars 
or  aquarium. 

Method.  —  Look  for  eggs  in  shallow  fresh-water  ponds  late  in 
March  or  early  in  April.  Collect  some  eggs  and  place  them  in  a 
shallow  aquarium  with  some  algae  in  a  sunny  place. 

Observations.  —  Notice  that  the  eggs  look  like  little  black 
dots  in  a  mass  of  jelly.     Is  their  color  uniform? 

The  collected  eggs  have  probably  been  fertilized.  They  were 
laid  in  the  water  by  the  female  ;  the  males  fertilizing  them  by  plac- 
ing sperm  cells  on  them;  as  soon  as  the  eggs  were  laid.  After 
laying,  the  thin  albuminous  coating  with  which  they  are  covered 
swelled  up  and  they  stuck  together. 

Examine  some  of  the  eggs  under  a  magnifying  glass.  Some  of 
them  have  probably  begun  to  segment  (divide  into  many  cells). 
Which  side  of  the  egg,  the  black  or  white  side,  seems  to  be  broken 
into  smaller  cells? 

NOTE.  —  Tho  white  side  is  filled  with  yolk,  or  food. 

Conclusion.  —  Write  a  paragraph  tellinii;  \v\wvo  frogs  lay  eggs, 
how  the  eggs  are  fertilized,  and  how  they  are  |)n)tected  after 
fertilization. 


168  THE   FISH   AND   FROG 

Problem  147 :  To  study  conditions  favorable  for  develojnnent 
offj^ogs'  eggs. 

Materials.  —  Live  frogs'  eggs,  glass  dishes. 

a.  Temperature 

Method.  —  Place  some  eggs  in  shallow  dishes.  Place  one  lot  in 
a  moderately  warm  room,  another  in  a  cold  room,  and  a  third  in 
an  ice  box. 

Observations.  —  Watch  and  record  results  daily  for  two  weeks. 

Conclusion.  —  What  is  the  relation  between  temperature  and 
the  development  of  frogs'  eggs? 

b.   Oxygen 

Method.  —  Place  a  large  number  of  eggs  in  a  dish  containing 
one  quart  of  water.  Place  a  few  eggs  from  the  same  egg  mass  in 
another  dish  containing  a  like  amount  of  water.  Place  both 
dishes  where  they  receive  the  same  conditions  of  light  and  heat. 

Observations.  —  Make  and  record  operations  daily  for  two 
weeks. 

Conclusion.  —  1.  Which  lot  receives  the  more  oxygen  per  egg? 
Explain. 

2.    Does  oxygen  affect  the  development  of  frogs'  eggs? 

Prohlem  148:  To  study  the  ryietamorphosis  of  the  frog. 

Materials.  —  Wax  models  of  development  of  frog,  living  or 
preserved  specimens  of  various  stages,  charts,  and  young  and  old 
stages  of  tadpoles  in  shallow  dishes. 

Method  and  Observations.  —  Using  the  wax  models,  try  to  find 
the  chief  differences  in  the  development  of  this  egg  as  compared 
with  the  egg  without  any  yolk.  Can  you  find  any  gastrula  stage 
here?  Look  at  the  model  cut  in  section  to  answer  this  point. 
(See  also  page  245,  Civic  Biology.) 

Trace  the  changes  from  the  time  the  egg  segments  to  the  time 
it  becomes  a  free-swimming  tadpole.  Where  are  the  gills  located 
at  first?  What  kind  of  mouth  parts  does  the  tadpole  seem  to 
have  ?     Notice  the  sucker  and  the  horny  jaws. 

How  would  the  early  stage  of  the  tadpole  breathe  ?     What  sort  of 


PROBLEM   QUESTIONS 


109 


food  must  it  of  necessity  eat?  Using  the  models,  charts,  and  hving 
specimens,  now  compare  the  later  stages  of  the  tadpole  with  those  of 
its  earhest  life.  Are  external  gills  always  present?  If  not,  what 
becomes  of  them?  Examine  the  internal  gills  in  the  older  tad- 
poles. Also  try  to  find  out  why  some  tadpoles  seem  to  (-(jme  to  the 
surface  of  the  water,  swallow  a  bubble  of  air,  and  then  go  under 
the  water  again. 

NOTE. — There  is  a  stage  in  the  life  of  the  tadpole  when  it  uses  both  Kills  and 
lungs  in  breathing. 

At  what  stage  of  the  metamorphosis  does  the  ta(li)ole  breathe 
by  internal  gills?  By  both  lungs  and  gills?  ^^'hi{•h  grow  first,  the 
front  or  hind  legs?  What  becomes  of  the  tail?  Are  there  any 
changes  in  the  appearance  of  the  mouth  in  an  older  tadpole  ?  Are 
there  teeth  in  the  mouth  of  a  tadpole  ?     A  frog  ? 

Conclusion.  —  What  changes  take  place  during  the  life  of  the 
tadpole  and  how  do  these  changes  fit  it  for  the  life  which  it  has  to 
lead  ? 

Problem  149 :  To  work  out  a  comparison  of  development  of 
the  vertebrates. 

Method.  —  Fill  out 
a  table  like  the  accom- 
panying. 

Conclusion.  —  In 

which    of    the    above 

animal  groups  do  the 

eggs    have    the    best 

likelihood  of  reaching 

development   into 

adults  ?    Explain  your 

answer. 

Problem   Questions 

1.  What  do  we  mean  by  adaptation  to  environment?  Illus- 
trate with  certain  organs  in  a  fish  ;  in  a  frog. 

2.  Might  color  be  an  adaptation?     Give  examples. 

3.  Might  habits  of  life  Ik^  adaptations  or  the  results  of  adajita- 
tions?     Explain. 


Fi^K 

Fro^ 

Bird 

Muinmul 

Niimber 
of^ggS 

Protection 
0/  Eggs 

Ca  re 

Probability 

of    Growths 
of    l&ggS 

170  THE  FISH   AND   FROG 

4.  Compare  breathing  in  the  fish,  in  the  frog,  and  in  your  own 
body.     What  especial  adaptation  do  you  note  ? 

5.  Why  do  some  fishes  lay  more  eggs  than  others? 

6.  What  have  life  habits  of  fishes  to  do  with  their  possible 
extermination  through  overfishing? 

7.  What  is  artificial  propagation  of  fishes? 

8.  Some  kinds  of  fish  eggs  are  provided  with  a  minute  drop 
of  oil  in  each  egg.  Of  what  use  might  this  be  in  the  development 
of  the  egg  ? 

9.  Why  are  many  more  sperm  cells  manufactured  than  egg 
cells  in  a  cod  ?  Explain  with  reference  to  the  egg-laying  habits  of 
the  fish. 

10.  Name  ten  food  fishes  that  are  cheap  in  your  locality ;  ten 
that  are  expensive.     Why  are  they  either  cheap  or  expensive? 

11.  What  are  the  amphibia  and  why  are  they  so  called? 

12.  How  is  a  frog  fitted  to  live  in  water ?     On  land? 

13.  Do  fishes  and  frogs  lay  their  eggs  at  any  especial  time  of 
year?     Give  examples. 

14.  How  does  the  development  of  a  frog  differ  from  that  of  a 
fish? 

15.  Explain  the  term  metamorphosis. 

16.  What  are  the  chief  enemies  of  the  frog?     How  is  it  pro- 
tected from  these  enemies? 

17.  How  may  frogs  and  toads  be  useful  to  man? 

18.  How  are  the  eggs  protected  and  from  what  enemies? 

19.  Of  what  use  is  the  yolk  of  an  egg  in  development  ? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XVI.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chaps.  XXII,  XXIII.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XXII.    American  Book  Company. 

FISH 

Bulletins  of  the  U.  S.  Commission  of  Fish  and  Fisheries.  (Write  to  the  Com- 
mission.) 

Butler,  The  Codfish  —  its  Place  in  American  History.  Transactions  Wisconsin 
Academy  of  Science,  Vol.  IX,  p.  261,  1898. 

Green  and  Roosevelt,  Fish  Hatching  and  Catching.     Rochester,  N.  Y. 

Johnstone,  Conditions  of  Life  in  the  Sea.     G.  P.  Putnam's  Sons. 

Jordan,  Fishes.     Henry  Holt  and  Company. 


REFERENCE   BOOKS  171 

Jordan  and  Evermann,  American  Food  and  Game  Fishes.  Doiihleday,  Pa«c  and 
Company. 

Lydcll,  Habits  and  Culture  of  Black  Bass.  Bulletin  I'.  S.  l-'isli  ronimission,  1902; 
Report  Indiana  Fish  C'omnii.s.sion,  11)01. 

Mather,  Modern  Fish  Culture  in  Fresh  and  Salt  Water.  I-'ori'st  .in.l  Sfrc.un  F'ul.- 
lishing  Company. 

Pahlow,  The  Wonders  of  the  Deep.     Cosmopolitan  Magazine,  .Inly,  HlOS. 

Reed,  The  Study  of  Fishes.  Cornell  University  Nature  Study  Quarterly,  No.  8, 
January,  1901. 

Reighard,  Breeding  Habits  aiui  Development  of  Black  Bass.  University  of  Michi- 
gan, 1907. 

Report  of  Fish  Commission,  1900. 

Townsend,  Cultivation  of  Fishes.     New  York  Zoological  Society. 

FROGS 

Dickerson,  The  Frog  Book.     Doul)leday,  Page  and  Company. 

Ecker,  The  Anatomy  of  the  Frog.     The  Macmillan  Company. 

Frogs,  Pigmies  and  Giants  by  Feeding.     Literary  Digest,  January  3,  1914. 

Holmes,  Biology  of  the  Frog.     The  Macmillan  Company. 

Morgan,  Development  of  Frogs'  Eggs.     The  Macmillan  Company. 

The  Usefulness  of  the  Toad.  Farmers'  Bulletin  19G,  U.  S.  Department  of  Agri- 
culture. 

Workman,  The  Toad  as  a  Garden  Benefactor.  House  and  Garden  Magazine,  March, 
1910. 

BIRDS 

Apgar,  Birds  of  the  United  States.     American  Book  Company. 

Baynes,  New  Method  of  Bird  Study.     Literary  Digest,  January  17,  1914. 

Beal,  Some  Coinmon  Birds  in  their  Relation  to  Agriculture.  FarnuTs'  Bulletin  54, 
U.  S.  Department  of  Agriculture,  1898. 

Beal  and  McAtee,  Food  of  Some  Well-known  Birds.     Farmers'  Bulletin  oOG,  1912. 

Beebe,  The  Bird.     Henry  Holt  and  Company. 

Beebe,  Domestication  of  Wild  Birds,     Nation,  April  9,  1914. 

Blanchan,  Bird  Neighbors.     Doubleday,  Page  and  Company. 

Bryant,  Number  of  Insects  Destroyed  by  Western  Meadow  Larks.  Science,  December 
20,  1912. 

Burroughs,  Birds  and  Bees.     Houghton  Mifflin  Company. 

Chapman,  Handbook  of  the  Birds  of  Eastern  North  America.  D.  Ai)pleton  and 
Company. 

Clarkin,  Who  Killed  Cock  Robin f     Everybody's  Magazine,  January,  1910. 

Dearborn,  How  to  Destroy  English  Sparrows.  Farmers'  Bulletin  383,  L'.  S.  Depart- 
ment of  Agriculture,  1910. 

Dugmore,  Bird  Homes.     Doubleday,  Page  and  Company. 

Fisher,  The  Economic  Value  of  Predacious  Birds  and  Mammals.  VearlM)«)k,  De- 
partment of  Agriculture,  190S. 

Forhush,  Game  Birds,  Wild  Fowl,  and  Shore  Birds.  Massachusetts  lininl  ..f  Airri- 
culture. 

Forbush,  Useful  Birds,  their  Protection.     Massachusetts  Board  of  .\grirulture. 

Hammond,  My  Friend  the  Partridge.     Forest  and  Stream  Publishing  Company. 


172 


THE   FISH   AND   FROG 


Henshaw,  Does  it  Pay  the  Farmer  to  Protect  Birds?     Yearbook,  Department  of 

Agriculture,  1907. 
Job,  Triumphs  of  Bird  Protection.     Harpers  Magazine,  July,  1909. 
Job,  //o»'  to  Study  Birds.     Outing  Publishing  Company. 
Job.  The  Sport  of  Bird  Study.     Outing  Publishing  Company. 
Kinisey,  Why  the  Birds  are  Decreasing.     Bird  Lore,  July,  1914. 
Miller,  The  Bird,  Our  Brother.     Houghton  Mifflin  Company. 
Miller,  Little  Brothers  of  the  Air.     Houghton  Mifflin  Company. 
Pearson,  Economic  Value  of  Birds.     Craftsynan,  January,  1913. 
Walter,  Wild  Birds  in  City  Parks.     Mumford. 
Ward,  Making  Bird  Houses.     Country  Life,  February,  1914. 

Weed  and  Dearborn,  Birds  in  their  Relation  to  Mail.     J.  B.  Li])pincott  Company. 
Wright  and  Coues,  Citizen  Bird.     The  Macmillan  Company. 


XVII.   HEREDITY,    VARIATION,    PLANT   AND   AMMAL 

BREEDING 

Problems.  —  To  determine  what  makes  the  off sj, vine!  of  ani- 
JYials  or  plants  tend  to  he  like  their  f)arents. 

To  determine  what  makes  the  nffsjn^ii}^  of  animals  and 
plants  differ  from  their  parents. 

To  learn  about  some  methods  of  plant  and  animal  breeding. 

(a)  By  selection. 

(b)  By  hybridizing. 
(e)   By  other  methods. 

To  learn  about  some  methods  of  improving  the  human  race. 

(a)  By  eugenics. 

(b)  By  euthenics. 

Suggestions  for  Laboratory  Work 

Laboratory  exercise.  —  On  variation  and  heredity  among  members  of 
a  class  in  the  schoolroom. 

Laboratory  exercise.  —  On  construction  of  curve  of  variation  in  meas- 
urements from  given  plants  or  animals. 

Laboratory  demonstration.  —  Stained  egg  cells  (ascaris)  to  show  cliro- 
mosomes. 

Laboratory  demonstrations.  —  To  illustrate  the  purt  phiyed  in  phiiit  or 
animal  breeding  by 

(a)  selection. 

(6)  hybridizing. 

(c)  budding  and  grafting. 

Laboratory  demonstration.  —  From  charts  to  illustrate  how  human 
characteristics  may  be  inherited. 

To  THE  Tkaciier.  —  T\w  cont.onts  of  this  oh:ii)t(M-  will  i>r()l)al»l\-  prove  of  morr 
interest  and,  if  seriously  taken  up  l)\-  (eaclier  and  pui)ils,  of  more  lasting  value  than 
any  other  part  of  the  eovu'se.  'V\\v  immense  siKnili<'anee  of  variation  and  heredity 
and  the  application  of  these  factors  in  euKenics  eertaii»ly  make  a  theme  of  vital 
interest.  The  direct  teaching  of  sex  hygiene  in  the  public  sccomlary  school  is  not 
recommended,  both  because  of  lack  of  preparation  (ui  the  part  of  teachers.  l>ecauso 
of  the  intimacy  of  contact  rcciuired  lietween  teacher  and  pupil,  making  work  with 

173 


174 


HEREDITY  AND   VARIATION 


large  groups  impracticable,  and  because  the  proper  place  for  such  direct  teaching 
is  in  the  home.  It  is,  however,  the  function  of  biology  to  teach  the  primary  facts 
known  about  reproduction  and  heredity  as  applied  in  plant  and  animal  breeding. 
On  these  facts  the  child  of  to-day  will  build  for  the  experiences  of  to-morrow. 

JProhle^n  150 :  To  deterinine  if  there  is  individual  variation 
in  any  one  measurement  of  the  members  of  a  given  class. 

Materials.  —  String,  ruler. 


14 


15 


16 


17 


18 


19 


Method.  —  With  the  string  carefully  measure  the  circumfer- 
ence of  your  right  wrist. 

Observations.  —  Verify  your  figures  by  having  your  neighbor 
take  the  measurement  for  you.     Do  the  same  thing  for  him.     The 


PROBLEAI    150 


i:r, 


instructor  will  give  you  an  individual  numl)or.  Hand  in  your 
results  with  your  number  to  one  pupil  of  the  elass  who  will  lahulate 
the  figures  on  the  board. 

Make  a  j2;rapli  showin<;-  the  individual  variation  in  circumference 
of  the  wrist  in  the  members  of  your  class. 

Conclusion.  —  Is  there  variation  in  this  measurement  amcjn^  the 
members  of  your  class? 


20 


Zl 


2^ 


23 


2  1 


2^r 


NOTE.  —  Exercises  on  variation  am  numerons  and  may  bo  worked  out  from 
charts,  from  collected  material  showing  variations,  or  from  work  done  by  pupils  in 
the  field.  In  every  case  where  possible,  a  graph  should  be  made  to  illustrate  the 
normal  and  the  variation  from  the  normal.  The  exercise  that  follows  will  show 
the  method  to  be  used. 


176 


HEREDITY   AND   VARIATION 


Problem  151 :  To  show  variation  in  a  given  class. 

Materials.  —  Figures  on  pages  174,  175.     Later  the  measure- 
ments of  the  individual  boys  or  girls  of  a  class. 


a.  Variation   in    Height 

Method  and  Observations.  —  Using  the  figures  on  pages  174,  175 
have  the  members  of  the  class  place  on  graph  paper  a  dot  for 

each   boy  seen  in  the 

■Number  of  Boy  nlafp     falririD-    thpm    in 

l^   34567  89  10111213141516171819  20  212^232423      y^'^^'^J     tdiviiig     tllClll    Hi 

numerical  order. 
Connect  the  points 
made.  Notice  the 
irregularity  of  the  hne 
formed. 

Now  rearrange  the 
boys  so  that  the  tall- 
est is  at  one  end  of 
the  line  and  the  short- 
est at  the  other  end, 
with  those  of  various 
heights  graded  in  be- 
tween. Place  dots  on  graph  paper  as  in  previous  exercise.  What 
difference  do  you  notice  in  the  line  made?  The  accompanying 
graph  shows  the  variation  in  height  of  the  boys. 

But  these  boys  differ  slightly  in  mentality,  considerably  in 
height,  considerably  in  weight.  Is  there  any  relation  between  the 
height  and  weight  in  a  given  group  of  boys? 

Note.  —  In  the  following  figure  the  line  xy  represents  the  normal  curve  of 
weight  and  height  relation  obtained  by  weighing  and  measuring  thousands  of  boys. 


ft  In, 
5.10 
59 
58 
57 
56 

55 

J.4 

5.3 

SZ 

5.\ 

5o 

4U 

4.10 

4  9 

4.8 

4.7 

46 


14  9    15  8    5  6   17  21   3    7  16  12  IB  4  ?  23  lo  1911  22  2524  20  1  13 

'S»oy-S     vearrctrvgecl 


b.  To  Form  a  Curve  Showing  the  Relation  of  Weight  to  Height 

in  a  Given  Class 

Method.  —  Notice  that  a  boy  of  4  feet  5  inches  should  weigh 
65  pounds,  while  a  boy  5  feet  11  inches  should  weigh  170  pounds. 
Knowing  your  own  height,  note  what  your  weight  should  be. 


PROBLEM    152 


177 


But  wc  find  that  most  of  us  (lifTcT  slijr},tly  from  th(Miormal  and 
in  the  class  represented  the  first  boy  is  o  feet  10  inches  tall  and 
weighs    140    pounds,    while    the    boy   numljei-    10    is    l.ui    .')    feet 


5    inches 


in     height 


S'/lO'O     OlflOrfl     O'Oo*)     o      «     "•OO'OOrfJ     o-     » 


and    also   weighs    140 
pounds. 

Arrange  your  graph 
paper  as  shown  at 
the  right,  with  the 
greater  weights  to  the 
left  of  the  page  and 
the  less  at  the  right. 
The  heights  are  to  be 
given  vertically  at  the 
left  side  of  the  paper. 
Now  pick  out  the 
members  of  the  class 
and  arrange  them  according  to  their  weights  and  heights,  placing 
a  dot  on  the  graph  paper  at  the  intersection  of  a  given  weight 
and  height  (as  in  the  case  of  the  boy  w^ho  weighs  165  pounds  and 
who  is  only  5  feet  4  inches  in  height).  After  you  have  finished 
connect  all  the  dots. 

Observations.  —  Does  the  line  formed  follow  the  normal  curve 
shown  in  the  chart  (line  xij)  or  does  it  vary?  How  do  you  ac- 
count for  this? 

Note. — This  curve  you  have  made  is  called  the  curve  of  correlation  l>et\veen 
weight  and  height.     We  might  also  correlate  age  and  weight,  or  age  and  height. 

Conclusion.  —  Using  the  above  method,  make*  a  curve  of  cor- 
relation showing  the  correlation  between  weight  and  height  in 
your  own  class. 

Problem  1!>2 :  Does  Jwredify  ])l(nj  any  part  in  our  lives  ? 

Materials.  —  Statistics  gathered  by  class  demonstrations. 

Method.  —  Let  each  member  of  the  class  try  to  bring  photo- 
graphs of  his  parents  and  if  possible  of  their  parents.  Write  down 
a  list  of  all  the  physical  traits  oi-  likenesses  you  can  find  in  your 
own  family.     Bring  in  written  or  verbal  reports  given  by  your 

HUNTER   LAB.    PROB.  —  12 


178  HEREDITY   AND   VARIATION 

parents  or,  if  possible,  your  grandparents,  telling  of  any  mental  or 
physical  characteristics  they  may  find  repeated  in  you  from  an 
earlier  generation. 

Observations.  —  Make  notes  on  as  many  striking  cases  of  in- 
heritance as  3^ou  can.     Compare  with  your  own  case. 

Conclusion.  —  1.  Are   we    in    any   ways    like   our   ancestors? 

2.  Are  mental  as  well   as   physical   characteristics   inherited? 

3.  Do  these  characteristics  seem  to  be  the  same  as  those  in 
your  ancestors? 

4.  What  do  we  mean  by  heredity? 

JProblein  153 :  To  study  the  jine  structure  of  an  egg  cell. 

Materials.  —  Egg  cells,  —  preferably  from  ascaris  (a  worm),  — 
stained  with  iron  haematoxylin  to  show  nucleus  and  chromosomes ; 
cells  showing  fertilization  stages  ;    charts ;    books. 

Observations.  —  Look  at  the  stained  cells  each  lying  within  a 
more  deeply  stained  capsule  or  covering.  What  structure  do  you 
find  within  it?  (Compare  figure  on  page  252,  Civic  Biology.) 
Look  for  the  chromosomes  within  the  nucleus.  How  many  can 
you  find? 

Note.  —  The  chromosomes  in  the  cells  of  the  body  are  always  definite  in  number 
for  every  species  of  animal  and  vary  from  two  in  ascaris  to  over  150  in  Crustaceans. 
In  man  there  are  sixteen.  The  chromosomes  are  believed  to  carry  the  hereditary 
qualities  from  one  generation  to  the  next. 

Examine  stained  specimens  that  show  fertilization  and  study 
carefully  the  figure  on  page  252,  Civic  Biology. 

Note.  —  Before  fertilization  takes  place,  the  number  of  chromosomes  in  each 
sperm  and  egg  cell  is  reduced  one  half.  Each  cell,  so  far  as  the  chromosomes  are 
concerned,  is  now  a  half  cell. 

Conclusion.  —  1.  What  happens  when  fertilization  takes  place? 
Study  the  figure. 

2.  If  new  characters  are  brought  to  the  new  animal  or  plant 
by  means  of  the  chromosomes,  then  what  part  would  fertilization 
play  in  heredity?     In  variation? 

Problem  154 :  How  selection  is  made. 

Materials.  —  Corn  on  ear,  photographs  or  description  of  differ- 
ent corn  plants. 


PROBLEM   15G  179 

Observations.  —  Compare  several  ears  of  corn  and  select  the 
ear  which  has  most  even  rows,  largest  kernels,  Qic.  Suppose  this 
ear  came  from  a  plant  which  had  l)ut  few  ears.  Would  you  select 
for  planting-,  ears  from  this  plant  or  ears  which  were  not  tjuile  .s(j 
perfect  from  a  plant  with  more  ears? 

Conclusion.  —  In  selecting  seed  for  planting,  what  are  some  of 
the  factors  to  be  kept  in  mind? 

Prohle^n  155 :  A  practical  result  of  selection. 

NOTE.  —  In  a  government  test  of  corn  to  increase  the  yield,  ears  were  chosen 
from  plants  that  gave  a  high  yield  and  the  seed  planted  in  rows.  Next  year  seed 
from  these  rows  was  planted  in  rows  alternating  with  seed  from  orjually  good-look- 
ing ears  from  the  same  kind  of  corn  grown  in  the  field.  Xote  the  results  with 
eight  pairs  of  ears. 

Pounds  of  Corn  yielded  by  the  Seed  of  One  E.\r 


FIELD   EARS 

EARS   FROM    HIGH-YI ELDING    PARENTS 

170     lbs. 

177.5  lbs. 

139.5   " 

180 

139      " 

199 

173      " 

197 

154      " 

172 

133      " 

176 

156.5   " 

194 

153      " 

200.5 

Observations.  —  What  per  cent  of  increase  was  there  from  the 
selected  corn? 

If  the  seed  from  the  field-grown  corn  yielded  42  ])ushels  per 
acre,  what  would  have  been  the  gain  per  acre  by  planting  seed 
from  the  selected  corn? 

Conclusion.  —  State  results  both  in  bushels  and  in  dollars,  corn 
being  worth  75  cents  per  bushel. 

Problem  156:  To  determine  some  means  of  selection  of  fruit 
trees  from  the  economic  stand /joint. 

Method  and  Observations.  —  Given  an  area  KHH)  feet  long  antl 
500  wide,  which  might  be  planted  as  follows  : 

(1)  Trees  20  feet  apart,  bear  after  five  years,  average  fiv(*  hun- 
dred apples  per  tree,  continue  bearing  twenty-five  years.  Apples 
wholesale  SI  per  hundred. 

(2)  Trees  22  feet  apart,  bear  after   seven    \ears,  average  six 


180 


HEREDITY   AND   VARIATION 


hundred  apples,  sell  $1.75  per  hundred,  continue  bearing  thirty 
years. 

(3)  Trees  25  feet  apart,  bear  after  six  years,  produce  four  hun- 
dred and  fifty  apples  per  tree,  continue  bearing  forty  years,  price 
$2.25  per  hundred. 

(4)  Trees  18  feet  apart,  bear  after  five  years,  average  three 
hundred  and  fifty  apples  per  tree,  bear  for  twenty  years,  average 
price  $3  per  hundred. 

(5)  Trees  30  feet  apart,  bear  after  six  years,  average  six  hun- 
dred and  fifty  apples  per  tree,  continue  bearing  twenty-five  years, 
average  price  $2  per  hundred. 

(6)  Trees  24  feet  apart,  bear  after  six  years,  average  five  hun- 
dred apples,  bearing  thirty  years,  average  price  $3.25  per  hundred. 

(7)  Trees  20  feet  apart,  bear  after  four  years,  average  two  hun- 
dred and  fifty  apples  per  tree,  continue  bearing  thirty  years,  price 
per  hundred  $3.75. 

Conclusion.  —  Which  of  the  above  would  you  choose  to  grow 
in  the  area?     Give  your  reasons. 


Problem  157 :  How  hyhridization  is  accomplished  in  flower- 
ing plants. 

Materials.  —  Plants  in  flower,  manila  bags,  camel's-hair  brush. 

Method.  —  Tie  a  manila  bag  over  a  growing  apple  or  pear  bud  (or 
any  other  large  available  flower)  that  is  about  to  open.     Remove 

from  another  flower  of  the  same  family,  but 
another  species,  all  parts  except  the  pistil,  be- 
fore the  flower  opens.  Cut  at  fine  marked 
W  on  figure.     Tie  a  bag  over  it  also. 

When  the  flower  in  the  first  bag  opens, 
transfer  some  of  the  pollen  to  the  stigma  of 
the  flower  without  stamens.  This  may  be 
done  by  means  of  a  small  camel's-hair  brush. 
Cover  the  surface  of  the  stigma  with  pollen. 
Label  the  stigma  thus  pollinated,  stating  the 
date,  and  all  data  concerning  source  of 
pollen,  etc. 

Observations.  —  Why   do   we    cover   the 


PROBLEM    150  ISl 

flowers  in  this  experiment?  Why  such  care  in  the  transfer  of 
pollen?     What  ought  to  happen  after  the  transfer  of  the  p(jllen? 

Conclusion.  —  1.  Remenihering  that  the  egjjj  cell  from  one  flower 
has  united  with  the  sperm  cell  of  anotlier  flower,  if  the  ()j)eration 
has  been  successful,  what  characters  ought  the  new  plant  to  have? 
Explain. 

2.  What  is  the  use  of  hybridization? 

Problem  158 :  Other  methods  used  in  filant  breeding. 

Materials.  —  Examples  of  budding,  grafting,  layers,  and  slips. 
Charts  and  texts. 

Observations.  —  Notice  carefully  what  has  been  done  in  making 
a  tongue  graft,  a  cleft  graft.  Study  the  steps  in  budding  (page  256, 
Civic  Biology).  Consult  any 
good  book  on  agriculture  to  see  ^PtO 

how  layering  and   slipping  are  

done. 

Conclusion.  —  1.    How  might 


Pc 


\^    w^ 


these  processes  enable  man  (a)  ^^    -^^    /^    /~^ 

to  form  new  kinds   of  plants?  /^     \^    \^    ^-X 


/, — "^J^ — ^\ 


(6)  to  reproduce  useful   plants 


{^0)  10  reproauce   useiui   pianis   ^^   -^^^    ^^    ^-^    ^-^  y^ 
(see  page  255,  Civic  Biologij)  ?      ^P    ^P    [^    \^    \^   \^ 

2.  What  kind  of  reproduc- 
tion is  this  called,  sexual  or 
asexual?  Explain  your  answer 
in  a  well- written  paragraph. 


Problem  159  :  To  deter^mine 
the  working  of  Mendel's  Law. 

Materials.  — Text  illustra-  £^^^^^£^     Qi 

tions,  charts,  material  illustrating 
Mendel's  Law. 

Observations.  —  Study  the  il- 


lustrations very  carefully.      No-  Diagram  to  Illustratk  Mkn^el'8  Law. 

•^                   '  White  Dominant,  Black  Recessive, 

tice  that  there  are  three  possi-  c'hauacteu. 

bilitiesof  offspring:  those  having  j^   first  RcMK^nition;    n,  second  prnora- 

dominant,  recessive,  and  mixed  tion ;  c.  third  gouerutiou. 


182 


HEREDITY   AND    VARIATION 


characters.  What  will  happen  if  animals  or  plants  having  pure 
dominant  characters  are  bred  together?  Pure  recessive  char- 
acters? Mixed  characters?  (See  chart.)  What  would  be  the 
proportion  of  dominants,  recessives,  and  mixed  offspring  in  the 
next  generation  if  breeding  continued  as  in  A  ? 

Conclusion.  —  Why  is  Mendel's  Law  of  great  value  to  plant  and 
animal  breeders?     Explain. 

Problem,  160:  To  determine  some  means  of  bettering,  physi- 
cally and  mentally,  the  human  race. 

Materials.  —  Charts  adapted  from  Davenport,  Goddard,  etc. 
showing  heredity  of  feeble-mindedness,  alcoholism,  epilepsy,  etc. 

Method.  —  Careful  study  of  the  charts  to  answer  the  questions. 

Observations.  —  If  one  of  the  parties  in  a  marriage  is  feeble- 
minded, are  any  of  the  children  likely  to  be  feeble-minded? 

If  both  parties  in  the  marriage  are  feeble-minded,  what  is  the 
likeUhood  of  the  children  being  feeble-minded? 


©-xlA] 


-      ^  J^  JL      I 

(S)tIaI  E]  E]  [n 


I 


^^SMS 


N 


d.       C.  d. 


W]\nj\n]\ 


A  Chart  to  show  the    Inheritance  of    Feeble-mindedness.     The  Squares 
Represent  Males  ;    the  Circles,  Females. 

A,  alcoholic  ;  F,  feeble-minded;  N,  normal;  d.inf.,  died  in  infancy. 

Does  alcohol  have  any  effect  on  the  production  of  feeble-minded 
children  ? 

Look  at  the  left-hand  side  of  the  chart  shown  above.  Does 
feeble-mindedness  there  seem  to  be  a  dominant  or  recessive 
character?     Explain. 

Note  to  Teacher.  —  Other  problems  of  a  similar  nature  may  be  taken  up  and 
discussed  with  seriousness  and  exceptional  interest  even  in  mixed  classes.  The 
child  is  at  the  receptive  age  and  is  emotionally  open  to  the  serious  lessons  here 
involved. 


PROBLEM   102  183 

Conclusion.  —  Should  foohlo-mindod  porsons  bo  allowed  to 
marry  ? 

Problem  IGl :  Are  ^ood  mental  parts  or  quaUticfi  cajuOjlc  of 
transmission  f row  parent  to  (•Jiild? 

Materials.  —  Charts,  reference  books,  etc. 

Observations.  —  Study  the  chart  to  see  if  artistic  ability  may 
be  inherited?  Think  of  any  case  in  your  family  oi  inheritance  of 
some  mental  trait,  such  as  musical  ability. 

Conclusion.  — Are  mental  traits  handed  down? 

Problem  1G2 :  Does  control  of  our  environment  have  anyth  ing 
to  do  with  the  problem  of  race  betterment? 

Method.  — A  study  of  your  own  environment. 

Observations.  —  Remembering  that  certain  factors  of  the  en- 
vironment react  upon  the  health  and  vitality  of  the  people  living 
within  that  environment  and  remembering  also  that  certain  germ 
diseases  may  enter  the  body  through  body  openings  or  even 
through  scratches  or  cuts,  then 

(1)  How  might  dirty  streets,  stores,  and  houses  affect  health 
in  a  neighborhood  ? 

(2)  How  might  the  milk  or  water  supply  affect  the  health  in  a 
given  neighborhood? 

(3)  What  effect  might  improper  or  insufficient  food  have  upon 
persons  within  a  given  locality? 

(4)  How  might  any  of  these  factors  affect  the  health  of  mothers 
with  newly  born  children? 

(5)  Might  such  factors  as  mentioned  above  alfect  these  babies? 
If  so,  how? 

(6)  Knowing  what  we  do  about  disease  germs,  should  we  use 
public  drinking  cups?     Explain. 

(7)  How  might  public  roller  towels  be  dangerous? 

(8)  What  other  factors  of  the  environment  might  work  against 
a  healthy  race?     Explain. 

Conclusion.  -  1.  What  factors  of  (he  enviromnent  have  to  do 
with  the  betterment  of  tlu^  race? 

2.  How  could  you  imi)rove  your  own  environment  ? 


184  HEREDITY   AND   VARIATION 

Problem  Questions 

1.  What  do  we  mean  by  variation?     Heredity? 

2.  Show  how  these  factors  work  in  plant  or  animal  breeding. 

3.  What  is  hybridization  ? 

4.  AVho  is  Luther  Burbank  and  what  has  he  done? 

5.  Why  should  farmers  select  seeds  with  great  care? 

6.  What  part  of  egg  and  of  sperm  cells  has  to  do  with  heredity? 

7.  Who  was  Mendel,  and  what  is  his  law? 

8.  What  did  De  Vries  do  in  the  problem  of  heredity? 

9.  What  is  meant  by  eugenics  ? 

10.  What  is  meant  by  euthenics? 

11.  How  might  alcohol  play  a  part  in  the  problem  of  heredity? 
.(See  Civic  Biology,  pages  289-294,  361-372.) 

12.  What  have  clean  thoughts  to  do  with  a  clean  body? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XVII.     American  Book  Company. 

Hunter,  Elements  of  Biology,  pp.  80,  81.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  pp.  81,  83.     American  Book  Company. 

Allen,  Civics  and  Health.     Ginn  and  Company. 

Bailey,  Plant  Breeding.     The  Macmillan  Company. 

Bailey,  Survival  of  the  Unlike.     The  Macmillan  Company. 

Barr,  Mental  Defectives.     P.  Blakiston's  Son  and  Company. 

Bergen  and  Caldwell,  Practical  Botany,  Chap.  XXIII.     Ginn  and  Company. 

Bigelow,  Sex  Instruction  as  a  Phase  of  Social  Education.     American  Medical  Asso- 
ciation, Chicago. 

Blatchford,  Not  Guilty.     Albert  and  Charles  Boni. 

Blood  Will  Tell.     Independent,  July  27,  1914. 

Bulletins  and  educational  pamphlets  1  to  6.     Society  of  Sanitary  and  Moral  Pro- 
phylaxis. 

Campbell,  Plant  Life  and  Evolution.     Henry  Holt  and  Company. 

Castle,  Heredity.     D.  Appleton  and  Company.  ; 

Circulars  1-4.     Chicago  Society  of  Social  Hygiene.  ■ 

Conklin,  Heredity  and  Environment.     Princeton  University  Press.  ■ 

Coulter,  Castle,  East,  Tower,  and  Davenport,  Heredity  and  Eugenics.     University        ; 
of  Chicago  Press.  i 

Darwin,  On  the  Origin  of  Species  by  Natural  Selection.     D.  Appleton  and  Company. 

Davenport,  Domesticated  Animals  and  Plants.     Ginn  and  Company. 

Davenport,  Heredity  in  Relation  to  Eugenics.     Henry  Holt  and  Company. 

Davenport,  Principles  of  Breeding.     Ginn  and  Company. 

Dawson,  Right  of  the  Child  to  be  Well  Born.     Funk  and  Wagnalls  Company. 

De  Vries,  Plant  Breeding.     Open  Court  Publishing  Company. 

Duggall,  The  Jukes.     G.  P.  Putnam's  Son^. 


REFERENCE   BOOKS  185 

Elliott,  Botany  of  To-day,  Chap.  XXV.     Sccley  and  Company.  London. 

Ellis,  Problem  of  Race  Regeneration,  Chap.  I.      Moffat.  Yard  and  Coini)any. 

P'oerster,  Marriage  and  the  Race.     Advanced.     F.  A.  Stokes  Company. 

Forhush,  The  Coming  Generation.     D.  Appleton  and  Company. 

Goddard,  The  Kallikak  Family.     The  Macmillan  Company. 

Goddard,  Feehle-mindcdness.     The  Macmillan  Company. 

Hall,  Adolescence  and  Psychology.     Advancofl.     D.  .Vppleton  and  Company. 

YiaW,  J ohyi's  Vacations;  Chums;  The  Doctor's  Daughter ;  Life  Problems.  American 
Medical  Association,  Chicago. 

Harwood,  New  Creation  in  Plant  Life.     The  Macmillan  Company. 

Haynes,  Dog  Breeding.     Outing,  March,  1914. 

Hegner,  The  Germ  Cell  Cycle  in  Animals.     The  Macmillan  Company. 

Holmes,  The  Evolution  of  Animal  Intelligence.     Henry  Holt  and  Company. 

Jewett,  The  Next  Generation.     Ginn  and  Company. 

Johnson,  Sexuality  in  Plants.     Science,  February  27,  1914. 

Jordan,  The  Heredity  of  Richard  Roe.     American  Unitarian  Association. 

Jordan  and  Kellog,  Scientific  Aspect  of  Luther  Burbank's  Work.     Robertson. 

Kellicott,  The  Social  Direction  of  Human  Evolution.  D.  .\ppleton  and  Com- 
pany. 

Kellogg,  Darwinism  To-day.     Henry  Holt  and  Company. 

Lucas,  Animals  of  the  Past.     Doubleday,  Page  and  Company. 

Morgan,  The  Development  of  the  Frog's  Egg.     The  Macmillan  Company. 

Morley,  The  Spark  of  Life.     Revell  and  Company. 

Morley,  Song  of  Life.     McClurg  and  Company. 

Mottram,  Controlled  Natural  Selection.     Longmans,  Green  and  Company. 

Plant  Breeding,  Articles  as  follows:  Webber  and  Bcssey,  Yearbook,  Department 
of  Agriculture,  for  1899.  Hays,  Yearbook,  Department  of  .\Kriculture,  for 
1901.  Bailey,  World's  Work,  1902,  p.  1209.  Wickson,  Sunset  Magazine, 
December,  1901,  April,  1902,  February,  1903.  Harwood,  Scribner'a,  May, 
1904.     Garner,  Cosmopolitan,  July,  1904. 

Plumb,  Types  and  Breeds  of  Farm  Animals.     Ginn  and  Company. 

Punnett,  Mendelism.     The  Macmillan  Company. 

Pycraft,  Courtship  of  Animals.     Henry  Holt  and  Company. 

Reik,  Safeguarding  the  Special  Senses.     F.  A.  Davis  Company. 

Report  of  Committee  on  Matter  and  Methods  of  Sex  Education.  Advanced. 
American  Federation  of  Sex  Hygiene,  N.  Y. 

Richards,  Euthenics,  the  Science  of  Controllable  Environment.  Whitcomb  and  Bar- 
rows. 

Roosevelt,  Twisted  Eugenics.     Outlook,  January  3,  1914. 

Saleeby,  Parenthood  and  Race  Cultxire,     MolTat.  Yard  and  Company. 

Smith,  The  Three  Gifts  of  Life.     Dodd,  Mead  and  Company. 

Thompson,  Heredity.     John  Murray,  London. 

Torelle,  Plant  and  Animal  Children.  /f<»r  Iheii  Grow.  D.  C.  Heath  and  Com- 
pany. 

Wallace,   The  Geographical  Distribution  of  Animals.     Harper  :iiid  Brothers. 

Walter,  Genetics.     The  Macmillan  Company. 

Warbasse,  Medical  Sociology.     Advanced.      I).  .Vppleton  and  Company. 

Wasmann,  The  Problem  of  Evolution.  Paul.  Kegan,  Trench,  TrUlMier  and  Company, 
London. 


186  HEREDITY   AND   VARIATION 

Whethan,  The  Family  and  the  Nation.     Longmans,  Green  and  Company. 
Wile,  Sex  Education.     Advanced.     Duffield  and  Company. 
Williams,  Every  Woman  her  own  Burhank.     Good  Housekeeping,  April,  1914. 
Williams,  With  Burhank  on  the  Lawns.     Good  Housekeeping,  September,  1914. 
Winship,  Jukes-Edwards  —  A  Study  in  Education  and  Heredity.     R.  L.  Myers  and 
Company. 


XVIII.   THE   HUMAN    MACHINE   AND    ITS    XEFDS 

Problem.  —  To  obtain  a  general  uiiderstai} d i n ^  of  ihr  jtarts 
and  uses  of  the  bodily  machine. 

Laboratory  Suggestions 

Demonstration.  —  Review  to  show  that  the  human  body  is  a  complex 
of  cells. 

Laboratory  demonstration  by  means  of  (a)  human  skeleton  and  (/>) 
manikin  to  show  the  position  and  gross  structure  of  the  chief  organs  of 
man. 

To  THE  Teacher.  —  As  in  certain  of  the  previous  chapters,  the  student  here 
takes  a  preliminary  view  of  the  general  problem  that  lasts  for  the  rest  of  his  course 
in  biology,  i.e.,  that  of  adaptation  to  function  in  the  human  body.  A  general  sur- 
vey gives  an  initial  interest  in  problems  which  are  solved  later  ;  it  defines  the  future 
problems  and  marks  the  beginning  of  some  new  concepts.  Certain  structures  of 
the  body,  as,  for  example,  bones  and  muscles,  are  now  treated  and  disniis.sed,  not 
because  of  their  non-importance,  but  because  of  the  time  demanded  by  the  more 
practical  questions  relating  to  dietaries  and  bodily  nutrition. 

Problem  163:  To  show  that  the  human  body  is  nuide  n]i  of 
cells. 

Materials.  —  Scalpel,  methyl  blue,  glass  slides,  cover  glasses, 
microscope. 

Method.  —  Scrape  mucous  lining;  from  the  moufli.  mount  on 
a  glass  slide,  and  stain  with  a  drop  of  dilute  metliyl  l)lu(\  Cover 
with  cover  glass  and  examine  under  microscope. 

Observations. — The  large  irreguUir  bodies  with  dark  blue 
bodies  within  them  are  flat  cells  {epithelium)  from  the  lining  of 
the  mouth.  What  are  these  dark  blue  structtu'es  within  tlie  cell? 
(The  small  dots  or  rods  stained  deep  blue  are  Imdivin.) 

Cells  from  other  parts  of  the  body,  ghuid,  nuiscle.  nerve,  etc., 
should  be  demonstrated  luuhM-  the  compoimd  microscope. 

Conclusion.  —  What  are  the  units  of  l)uilding  material  in  the 

body  ? 

187 


188 


THE   HUMAN   MACHINE 


Problem  164:  To  find  out  some  functions  of  the  shin. 

Materials.  —  Hand  lens,  ether  or  alcohol,  large  glass  jar,  two 
thermometers,  model  or  chart  of  skin. 

Method  and  Observations.  —  Find  out  whether  all  parts  of  the 
skin  are  equally  sensitive,  by  touching  with  the  sharp  point  of  a 
pencil.  Cool  a  large  glass  jar,  and  hold  the  hand  and  wrist  in 
the  jar  for  a  few  moments,  closing  the  opening  of  the  jar  with  a 
cloth  or  a  towel.  What  collects  on  the  inner  surface  of  the  jar? 
What  happens  when  you  take  violent  exercise?  Weigh  yourself 
before  and  after  a  period  of  hard  work  in  the  gymnasium.  Is 
there  any  loss  in  weight?  How  do  you  account  for  it?  Place 
a  few  drops  of  ether  or  alcohol  on  the  back  of  the  hand  and  note 
the  evaporation  of  the  liquid.  What  sensation  do  you  feel  while 
the  evaporation  takes  place? 

Study  the  model  or  figure,  page  342,  Civic  Biology.     Locate  the 

two  layers  by  means  of  your  textbook.  Find 
and  describe  the  sweat  glands,  oil  glands,  and 
sense  organs.  Draw  a  diagrammatic  sketch  of 
the  model  and  label  all  parts.  Write  a  state- 
ment giving  the  function  of  each  part. 

Conclusion.  —  1.    Is    the    skin    an    organ    of 
sensation  ? 

2.  What  passes  off  through  the  skin? 

3.  What  result  to  your  bodily  comfort  does 
this  last  function  have? 


Problem   165:    To  study   the  use  of  the 

muscles. 

Material.  —  Frogs  preserved  in  formalin. 

Method.  —  Remove  the  skin  from  the  hind 
leg  of  a  frog. 

Observations.  —  Note  the  "  flesh  "  forming 
the  muscle  of  the  leg.  (The  wide  part  or  helly  of 
a  muscle  is  attached  to  the  bone  by  a  tough 
tendon.)  Move  the  leg  by  pulling  the  foot  up 
and  down.  What  effect  does  this  have  on  the 
muscle?     To  what   are  the  muscles  attached? 


Muscles  of  the 
Left  Leg  of  the 
Frog. 

6,  biceps  ;  g,  gastroc- 
nemius;  sm , 
s  e  m  i  -  m  c  m  b  r  a - 
nosus ;  tr,  triceps. 


PROBLEM   IGG  ISO 

At  how  many  points  are  they  attached?  Exi)lain  how  move- 
ment of  the  leg  results  from  contraction  (sliortenin^)  of  certain  of 
the  muscles.  What  must  occur  wiien  some  of  the  nniscles  con- 
tract? (Look  at  the  position  of  the  muscle  on  the  opjjcj.site 
side  of  the  leg.)  Note  the  shape  of  your  upper  arm.  To  what 
is  the  rounded  surface  due? 

Conclusion.  —  L  Why  do  muscles  cause  movement?  Explain 
fully. 

2.  What  use,  other  than  movement,  have  muscles? 

Problem  KiO :  To  study  the  structure  and  uses  of  the  skeleton. 

Materials.  —  Prepared  human  skeleton,  manikin. 

Observations.  —  Note  that  the  skeleton  is  divided  into  two 
groups  of  bones  :  a  main  framework  of  the  body,  the  axial  skeleton  ; 
and  a  framework  for  the  appendages,  the  appendicular  skeleton. 
In  life  the  bones  are  attached  to  each  other  by  tough  ligaments. 
Why  are  the  bones  jointed?  Notice  the  bones  of  the  head, 
skull,  and  face.  Knowing  that  the  skull  covers  part  of  the 
delicate  nervous  system,  the  brain,  what  would  you  say  its 
use  was? 

Note  that  the  backbone,  made  up  of  numerous  pieces  of  l)one. 
has  a  hole  running  through  it.  This  hole  contains  in  life  the  spinal 
cord. 

Attached  to  the  vertebrae  of  the  backbone  are  the  ribs.  Com- 
pare the  position  on  the  manikin.  What  is  one  use  of  the  ribs? 
Feel  your  own  ribs;  bend  forward,  and  take  a  full  breath.  What 
is  another  function  of  your  ribs?  (Remember,  to  obtain  move- 
ment, muscles  must  be  attached  to  bones.     Why?) 

Notice  that  the  arm  is  attached  to  the  main  skeleton  by  means 
of  two  bones,  the  collar  bone  and  the  shouldcM'  blade.  These 
bones  form  the  pectoral  girdle.  The  leg  is  in  the  same  way  at- 
tached to  a  group  of  strong  bones  called  tlie  pelvic  girdle. 

Notice  various  bones,  such  as  the  long  arm  bone  (iiunierus), 
shoulder  blade,  pelvic  bones,  the  spines  on  the  ribs,  for  roughness 

To  THE  Teacher.  —  A  demonstration  should  be  shown  .it  this  point  to  iUu.o- 
trate  the  structure  of  striated  and  phiin  muscU»  tissue.  Detailed  laboratory  work 
on  this  material  is  not  desirable. 


190  THE   HUMAN   MACHINE 

where  muscles  might  be  attached.  In  each  case  seek  a  place  for 
attachment  for  the  other  end  of  the  muscle. 

Conclusion.  —  1.  Write  a  statement  giving  three  general  uses  of 
the  human  skeleton.  Take  a  special  bone  or  bones  to  illustrate 
each  use. 

2.  Compare  the  skeleton  with  the  figure  on  page  268,  Civic 
Biology.     Make  a  drawing  to  identify  the  principal  bones. 

Problem  107:  To  find  the  relation  of  muscles  to  hones  in  the 
human  body. 

Method.  —  Using  the  diagrams  in  your  Civic  Biology,  page  269, 
work  out  the  different  classes  of  levers. 

Observations.  —  In  the  human  body  which  class  of  lever  is 
represented  when  we  raise  a  weight  in  the  hand  ?  What  kind  of 
lever  do  we  use  when  we  rise  on  the  toes?  W^hat  kind  of  lever 
do  we  use  when  we  nod  the  head? 

Conclusion.  —  1.  Prove  that  three  classes  of  levers  are  present 
in  the  human  body. 

2.  Find  another  example  of  each  kind  of  lever  in  the  human 
body. 

Problem,  16  S :  To  study  the  joints  of  the  human  body. 

Materials.  —  Human  skeleton. 

Method.  —  Study  the  following  joints  in  the  human  skeleton: 
arm  at  shoulder,  knee,  head  on  neck  bones,  bones  of  spinal 
column.     Move  them  in  each  case. 

Observations.  — •  Is  the  joint  hinge-like,  ball  and  socket,  gliding, 
or  rotary  ? 

Conclusion.  —  1.  How  many  different  kinds  of  joints  can  you 
find  in  a  skeleton? 

2.  What  are  their  specific  uses? 

Problem  KiO :  To  get  a  preliminary  survey  of  the  hiternal 
structure  of  the  human  body. 

Materials.  —  Manikin  and  charts  showing  organs  of  the  human 
body. 

Observations.  —  If  we  compare  the  human  body  to  a  machine, 
then  the  bones  and  muscles  are  the  framework.     Within  the  body, 


PROnLK:\I    IGO 


191 


partially  protected  ])y  the  ribs,  is  a  cavity,  tho  body  cnritt/,  divided 
into  two  uneciual  parts  by  a  wall  of  muscles,  the  diaphnujm.  'Hie 
body  cavity  contains  the  working  parts  of  the 
machine :  a.  The  organs  of  digestion,  gidlct, 
stomach,  small  intestine,  large  intestine,  the  liver 
and  pancreas  (two  digestive  glands),  and  tho 
spleen  (a  gland  connected  to  the  digestive 
organs),  b.  The  organs  of  respiration,  the 
lungs  and  tubes  which  conne(;t  them  with  the 
outside  of  the  body.  c.  The  organs  of  circu- 
lation, the  heart  and  blood  vessels.  d.  The 
organs  of  excretion,  the  kidrieys.  e.  Most  im- 
portant of  all  is  the  nervous  system.  This  con- 
sists of  the  brain  and  spinal  cord  with  the  nerves 
growing  out  from  them,  and  several  different 
sense  organs,  which  are  at  the  outside  of  the 
body  and  send  nerves  inward  to  connect  with 
the  central  nervous  system. 

Your  instructor  will  demonstrate  these  to 
you.  We  will  spend  most  of  the  remainder 
of  our  course  in  learning  more  about  the  use 
of  these  various  organs  in  the  human  machine. 

Conclusion.  —  1.  What  are  the  chief  organs 
of  the  human  body  cavity  ? 

2.  Which  of  these  are  in  the  body  cavity  and 
which  extend  into  other  parts  of  the  body? 

3.  Which  are  chiefly  outside  the  body  cavity 
but  send  branches  in?  (Get  help  from  j'our 
instructor  or  your  textbook,  page  271,  Civic 
Biology.) 

4.  Why  are  sense  organs  in  the  skin?     How  do  they  send  mes- 
sages to  other  parts  of  the  body? 


The  Organ's  •vnTiiiv 
THK  Human  ]i(>DY. 
Read  fuom  auove 

DOWN  : 

t,  tongue  ;  L,  larynx  ; 
cp,  gullet ;  /.  lung  ; 
//,  heart ;  *•/,  ster- 
num ;  s.c,  spinal 
cord  ;rf,  clia|ihragni ; 
L,  livor ;  N,  stom- 
ach ;  k,  kidney ;  p, 
pancreas ;  i.  small 
intestine ;  /.  large 
int«'stint' ;  a.  vermi- 
form iii>pendix:  li, 
bladder ;  R,  rectum. 


Problem  Questions 

1.  What  is  the  unit  of  structure  in  tho  liuninn  ])ody? 

2.  Why  do  the  cells  in  different  parts  of  the  IkhIv  differ  in  siiape 
and  size? 


192  THE   HUMAN   MACHINE 

3.  Of  what  use  is  the  skin  to  man? 

4.  Would  the  skin  serve  the  same  purposes  in  the  frog  as  in 
man  ? 

5.  Name  the  functions  of  muscles. 

6.  How  do  muscles  work?     Explain  fully. 

7.  Explain  the  difference  between  a  voluntary  and  an  involun- 
tary- muscle. 

8.  What  effect  would  working  of  the  muscles  have  upon  heat 
within  the  body?     Explain. 

9.  What  effect  might  muscular  work  have  upon  the  skin? 

10.  Why  are  the  muscles  arranged  in  pairs  ? 

11.  Name  three  uses  of  the  skeleton. 

12.  What  attaches  muscles  to  bones? 

13.  What  is  a  lever?     Give  examples. 

14.  Show  how  some  one  part  of  the  body  might  illustrate  the 
action  of  three  classes  of  levers. 

15.  Of  what  use  are  the  joints? 

16.  Explain  the  difference  between  a  break  and  a  sprain. 

17.  What  is  the  body  cavity? 

18.  Which  sets  of  organs  are  found  entirely  in  the  body  cavity? 

19.  Which  organs  are  found  partially  in  the  body  cavity? 

20.  Why  might  the  nervous  system  be  called  the  "  director  of 
the  body"? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XVIII.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chaps.  XXXI,  XXXII.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XXIII.     American  Book  Company. 

Davison,  Human  Body  and  Health  (Advanced),  Chap.  XVII.  American  Book 
Company. 

Goldmark,  Fatigue  and  Efficiency.     Charities  Publication  Committee. 

Gulick,  The  Gulick  Hygiene  Series.     Ginn  and  Company. 

Gulick,  Physical  Education  by  Muscular  Exercise.  P.  Blakiston's  Son  and  Com- 
pany. 

Hall,  Elementary  Anatomy.     American  Book  Company. 

Halliburton,  Kirkes  Handbook  of  Physiology.     P.  Blakiston's  Son  and  Company. 

Hammarsten,  Textbook  of  Physiological  Chemistry.     J.  Wylie  and  Son. 

Hawk,  Practical  Physiological  Chemistry.     P.  Blakiston's  Son  and  Company. 

Hough  and  Sedgewick,  The  Human  Mechanism,  Chap.  II.     Ginn  and  Company. 

Howell,  Physiology.     W.  B.  Saunders. 

Hutchinson,  Exercise  and  Health.     Outing  Publishing  Company. 


REFERKXCK    noOK^  193 

Hutchinson,  Athletics  and  the  Heart.     Oiitiuy  Maoazinv,  .]\\\y,  1910. 

Hutchin.son,  Errors  in  Exercise.     Outinu  Magazine,  April,  I'JIU. 

Overton,  General  Hygiene.     American  Book  Company. 

Pusey,  Care  of  the  Skin  and  Hair.     D.  Appleton  and  Company. 

Ritchie,  Human  Physiology,  Chap.s.  III-V.     World  Book  Company. 

Schafer,  Textbook  of  Physiology.     The  Macmillan  Company. 

Sharpe,  Laboratory  Manual  in  Biology,  pp.  21S-22o.     .American  Book  Company. 

Stewart,  Manual  of  Physiology.     ^^'.  B.  Saunders. 

Stiles,  Nutritional  Physiology.     W.  B.  Saunders. 

Verworn,  General  Physiology.     The  Macmillan  Company. 


HUNTER    LAB.    PllOB. 13 


XIX.   FOODS   AND   DIETARIES 

Problems,  — A  study  of  foods  to  determine: 

(a)  Their  nutritive  value. 

(b)  TJte  relation  of  worh,  environment,  age,  sejc,  and  digest- 
ibility of  foods  to  diet. 

(c)  Their  relative  cheapness. 

id)  The  daily  Calorie  requirement. 

ie)  Food  adulteration. 

(/)  The  relation  of  alcohol  to  the  human  system. 

Laboratory  Suggestions 

Laboratory  exercise.  —  Composition  of  common  foods.  The  series  of 
food  charts  supplied  by  the  United  States  Department  of  Agriculture 
makes  an  excellent  basis  for  a  laboratory  exercise  to  determine  common 
foods  rich  in  (a)  water,  (6)  starch,  (c)  sugar,  (d)  fats  or  oils,  (e)  protein, 
(/)  salts,  ig)  refuse. 

Demonstration.  —  Method  of  using  bomb  calorimeter. 

Laboratory  and  home  exercise.  —  To  determine  the  best  individual  bal- 
anced dietary  (using  standard  of  Atwater,  Chittenden,  or  Voit)  as  deter- 
mined by  the  use  of  the  100-Calorie  portion. 

Demonstration.  —  Tests  for  some  common  adulterants. 

Demonstration.  —  Effect  of  alcohol  on  protein,  e.g.,  white  of  egg. 

Demonstration.  —  Alcohol  in  some  patent  medicines. 

Demonstration.  —  Patent  medicines  containing  acetanilid.  Determi- 
nation of  acetanilid. 

To  THE  Teacher.  —  The  practical  work  in  this  chapter,  although  outlined  to 
take  not  more  than  two  to  three  weeks,  has  such  possibilities  of  interest  and  im- 
portance that  more  time  may  well  be  spent  in  its  consideration.  The  working  out 
of  an  individual  or  family  dietary  with  an  estimate  of  the  cost  is  an  exercise  that 
appeals  strongly  to  the  average  pupil.  Food  economy  and  the  balance  of  a  ration 
are  needed  topics  in  every  household  to-day. 

The  practical  correlation  of  work  in  biology  with  that  of  home  economics  is 
found  here.  It  might  well  be  worth  while  to  expand  this  side  of  the  course  with 
girls  so  that  several  weeks  be  devoted  to  the  practical  side  of  dietetics.     Much  of 

194 


PROBLEM    171  195 

the  laboratory  work  can  be  transferred  to  the  hilx)ratory  of  home  economics  or  to 
the  home. 

Problem  170:  How  to  deternvine  the  nutritive  value  of  fond . 

Materials.  —  Set  of  government  charts  on  food  values.  Tables 
on  pages  276,  278,  279,  Civic  Biology. 

NOTE.  —  Food  has  two  possible  vahaes  :  it  may  be  oxidizofl  to  release  enercy  or 
it  may  help  build  tissue.  The  burning  value  of  foods  may  ]>c  measured  by  heat 
units  called  Calories  (a  Calorie  is  the  amount  of  heat  needed  to  raise  the  tempera- 
ture of  a  kilogram  of  water  through  one  degree  centigrade).  Remember  food  is 
composed  of  nutrients,  water,  and  refuse.  Therefore  not  all  food  taken  into  the 
body  is  made  use  of. 

Observations.  —  In  the  chart  on  page  27G,  Civic  Biologij,  deter- 
mine the  actual  percentage  of  nutrients  in  beef,  potatoes,  oysters, 
and  corn  meal.     Do  all  foods  have  equal  nutritive  value? 

From  the  government  charts  make  a  table  in  which  you  will  place  : 

(a)  Ten  foods  rich  in  protein  (15  per  cent  or  more). 

(6)  Ten  foods  rich  in  carbohydrates  (50  per  cent). 

(c)  Ten  foods  rich  in  fat  (50  per  cent  or  more). 

(d)  Ten  foods  having  a  high  fuel  value  (1500  Calories  or  more 
per  pound). 

(e)  Ten  food  substances  that  are  over  50  per  cent  water.  IIow 
would  water  affect  the  cost  of  food,  providing  you  had  to  pay  for 
the  water? 

(/)    Five  foods  rich  in  mineral  salts. 

Conclusion.  —  In  your  opinion  which  of  the  foods  shown  are 
the  best  tissue-building  foods  ?  The  best  energy-producing  foods  ? 
Explain.  Remember  that  hving  matter  is  made  uj)  of  carbon, 
oxygen,  hydrogen,  nitrogen,  sulphur,  and  a  minute  amount  of 
mineral  salts. 

JProblem  171:  The  use  of  the  bortih  calorimeter.    (Optional.) 

The  bomb  calorimeter  may  be  demonstrated  by  the  instructor  and  its  mechan- 
ism explained.  Roys  should  be  urged  to  try  to  experiment  at  home  with  homemade 
apparatus.  An  interesting  series  of  home  experiments  on  the  burning  value  of 
different  food  sul)stances  worked  out  first  hand  will  do  much  toward  getting  indi- 
vidual interest  in  the  topic.  Cirls  should  ai)proach  this  entire  subject  from  the  side 
of  household  economics.  Much  work  can  be  done  in  household  economics  that  will 
be  scientifically  explained  in  the  biological  laboratory,  the  two  subject.s  giving  und 
taking  much  from  common  ground. 


196  FOODS   AND   DIETARIES 

The  experiments  of  Atwater  with  the  respiration  calorimeter  should  be  explained 
and  pictures  of  the  apparatus  shown  so  that  the  pupils  may  be  impressed  with  the 
delicacy  and  magnitude  of  the  experiments.  This  respiration  calorimeter  is  de- 
scribed by  Professor  Atwater  as  follows  : 

"Its  main  feature  is  a  copper- walled  chamber  7  feet  long,  4  feet  wide,  and  6  feet 
4  inches  high.  This  is  fitted  with  devices  for  maintaining  and  measuring  a  ventilat- 
ing current  of  air,  for  sampling  and  analyzing  this  air,  for  removing  and  measuring 
the  heat  given  off  within  the  chamber,  and  for  passing  food  and  other  articles  in  and 
out.  It  is  furnished  with  a  folding  bed,  chair,  and  table,  with  scales  and  appliances 
for  muscular  work,  and  has  telephone  connection  with  the  outside.  Here  the  sub- 
ject stays  for  a  period  of  from  three  to  twelve  days,  during  which  time  careful 
analyses  and  measurements  are  made  of  all  material  which  enters  the  body  in  the 
food,  and  of  that  which  leaves  it  in  the  breath  and  excreta.  Record  is  also  kept  of 
the  energy  given  off  from  the  body  as  heat  and  muscular  work.  The  difference 
between  the  material  taken  into  and  that  given  off  from  the  body  is  called  the  bal- 
ance of  matter,  and  shows  whether  the  body  is  gaining  or  losing  material.  The 
difference  between  the  energy  of  the  food  taken  and  that  of  the  excreta  and  the 
energy  given  off  by  the  body  as  heat  and  muscular  work  is  the  balance  of  energy, 
and  if  correctly  measured,  should  equal  the  energy  of  the  body  material  gained  or 
lost.  With  such  apparatus  it  is  possible  to  learn  what  effect  different  conditions 
of  nourishment  will  have  on  the  human  body.  In  one  experiment,  for  instance,  the 
subject  might  be  kept  qmte  at  rest,  and  in  the  next  do  a  certain  amount  of  muscular 
or  mental  work  with  the  same  diet  as  before,  then  by  comparing  the  results  of  the 
two,  the  use  which  the  body  makes  of  its  food  under  the  different  conditions  could 
be  determined  ;  or  the  diet  may  be  slightly  changed  in  the  one  experiment,  and  the 
effect  of  this  on  the  balance  of  matter  or  energy  observed.  Such  methods  and 
apparatus  are  very  costly  in  time  and  money,  but  the  results  are  proportionately 
more  valuable  than  those  from  simpler  experiments." 

The  experiments  of  Chittenden  should  also  be  explained.  (See 
Chittenden's  Nutrition  of  Man.) 

Atwater's  Calorimeter.     (See  diagram  on  page  197.) 

Atwater's  respiration  calorimeter,  an  apparatus  for  determining  the  income  and 
outgo  of  energy,  and  respiratory  products  of  the  human  body,  under  varying  con- 
ditions, consists  of  an  air-tight  copper  chamber,  insulated  from  the  surrounding 
air  by  a  zinc  casing  and  three  wooden  ones,  with  dead-air  spaces  between.  It  is 
provided  with  a  door  and  a  window  for  the  introduction  and  removal  of  food. 
Closely  attached  to  the  outside  of  the  copper  wall  are  304  thermoelectric  couples 
{A)  which,  electrically,  report  the  temperature  of  the  calorimeter  chamber  to  the 
observer's  table  {B).  The  temperature  of  the  chamber  is  maintained  as  nearly 
constant  as  possible  by  a  current  of  cold  water,  pumped  by  the  electric  pump 
(C)  through  the  cooling  tank  (D)  to  {E),  where  its  temperature  is  taken  just  before 
it  enters  the  large-surface,  winged  pipes  around  the  chamber.  When  the  water 
emerges  at  (F),  its  temperature  is  taken  again  and  its  volume  and  flow  measured 
at  the  water  meter  {G)  before  it  returns  to  the  pump.  From  these  data,  knowing 
the  rise  in  temperature  and  the  amount  of  water  so  raised,  the  amount  of  heat 
developed  within  the  calorimeter  may  be  computed.  The  flow  of  water  may  be 
regulated  so  as  to  carry  off  any  amount  of  heat  developed. 


PROP.LEM    172 


U): 


In  order  to  assure  accurate  work  on  the  respiratory  i^roduots,  the  system  of 
ventilation  is  also  a  closed  one.  The  vitiated  air  is  drawn  out  by  the  pipe  (//). 
and  then  through  a  double  row  of  vessels  of  sulphuric  acid  (/.  /,  /,  /)  to  remove 
water  vapor,  and  vessels  of  soda  lime  (./,  ./,  ./,  J)  to  remove  COt,  to  the  electric 
pump  (K).  From  here  it  is  returned  through  pipe  (L)  to  (A/),  where  any  deficiency 
in  oxygen  is  noted  and  remedied  from  a  tank  of  that  gas  before  it  is  pumped 
through  the  regulating  pans  {N,  N)  into  the  chamber. 

Method.  —  Using  the  diagram  and  explanation,  try  to  explain 
to  your  own  and  your  teacher's  satisfaction  the  working  of  the 
At  water  calorimeter. 

Conclusion.  —  What  is  the  practical  value  of  the  ai)paratus? 

Problem  172:  To  find  tJie  value  of  food  as  a  tissue  buildci^ 
cojnpared  with  its  cost. 

Method.  —  Use  the  tables  on  pages  198-201  ;  make  sure  you 
understand  the  various  column  headings. 

Note.  —  Foods  may  be  considered  cheap  if  they  furnish  more  than  .12  n'  a 
pound  of  protein  (the  tissue  builder)  for  10  cents  at  present  prices ;  medium  prictxl 


198 


FOODS  AND   DIETARIES 


if  they  furnish  from  .06  to  .12  pound  of  protein  for  ten  cents;  expensive  if  they 
furnish  less  than  .06  pound  of  protein  for  ten  cents. 

Conclusion.  —  1.  Pick  out  ten  cheap,  ten  medium,  ten  expensive 
tissue-building  foods. 

2.  In  which  of  the  following  groups  are  the  cheapest  protein 
foods  found  :  meats,  cereals,  vegetables,  fish,  shellfish,  dairy  prod- 
ucts, fruits?     Note  also  the  most  expensive. 

Prohlem  17'i  :  To  find  the  value  of  food  as  a  source  of  energy 
compared  with  its  price. 

Method.  —  Use  the  following  tables  as  suggested  above. 

NOTE.  —  Cheap  foods  give  more  than  1500  units  of  energy  for  10  cents  at  pres- 
ent prices ;  medium  priced  give  between  750  and  1500  units  of  energy  for  10  cents  at 
present  prices  ;  expensive  give  less  than  750  units  of  energy  for  10  cents  at  present 
prices. 

Conclusion.  —  1.  Find  ten  cheap  fuel- or  energy-giving  foods, 
ten  medium  priced,  and  ten  expensive  ones. 

2.  Can  you  find  ten  foods  that  are  cheap  both  as  energy  pro- 
ducers and  as  tissue  builders  ? 

NOTE.  —  An  interesting  exercise  on  economic  buying  of  foods  for  a  family  or  for 
individual  consumption  may  be  worked  out  from  this  table,  which  has  been  revised 
by  inserting  present-day  prices.  This  is  of  especial  value  in  connection  with  work 
in  home  economics. 

Comparative  Nutritive  Values  and  Prices  of  Food  Materials  ^ 


Price 

PER 

Pound 

IN  Cents 

Ten  Cents  will 
Purchase 

Protein 
in  lbs. 

Fat  and 

Carbo. 

Energy 

Calories 

Beef 

Porterhouse  steak 

Sirloin  steak   . 

32 

28 
28 
22 
22 

.050 
.058 
.079 
.070 
.077 

325 
370 

Round  steak  (top 
Chuck  steak   . 

round)       .... 

370 
420 

Plank  steak 

510 

1  Revised  by  John  W.  Teitz  of  the  Department  of  Biology,  De  Witt  Clinton 
High  School. 


PROBLEM    173 


199 


Comparative  Nutritive  Values  and   Prices   of   Food   Materials 

Continued 


Beef —  Continued 

Porterhouse  roast     .... 

Rib  roast 

Bottom  round 

Plate  (corned  beef)       .     .     . 
Shank  (soup  beef)    .... 

Veal 

Cutlets 

Loin  and  rib        

Leg 

Breast 

Neck  (stew  veal)      .... 
Knuckle  or  shank  (veal  broth) 

Mutton  and  Lamb 

Loin 

Leg 

Shoulder 

Neck  (stew  lamb)    .... 

Pork 

Ham,  fresh 

Ham,  smoked 

Shoulder,  fresh 

Shoulder,  smoked    .... 

Ribs  and  loins 

Fat  salt  pork 

Bacon 

Poultry 

Turkey 

Chicken 

Sea  Foods 

Bluefish 

Cod,  fresh 

Cod,  salted 

Halibut,  fresh 

Halibut,  smoked      .... 

Mackerel,  fresh 

Mackerel,  salt 

Salmon,  canned 


Pkice 

PER 
POCND 

IN  Cents 


30 
2o 
20 
10 
12 

30 
26 
25 
22 
20 
15 

30 
23 
20 
16 

23 
23 
18 
18 
24 
16 


32 
24 

14 
15 
16 
20 
25 
12 
15 
25 


Ten  Cents  will 
purchabe 


Protein 
in  lbs. 


Fat  and 
Carbo. 

En  E  HOY 

Calories 


.0.54 

.().■)() 
.()S2 

.i:w 

.107 

.060 
.065 
.063 
.098 
.080 
.138 

.046 

.()()5 
.060 
.18,3 

.067 
.062 
.067 
.078 
.056 
.012 
.042 

.052 
.058 

.072 
.112 
.110 
.072 
.07S 
.00«i 
.100 
.088 


:i50 
470 
300 
1200 
455 

170 
270 
215 
290 
255 
395 

490 
390 
370 

1480 

670 
730 

820 

7(>0 

()35 

2'295 

1265 

340 
325 

ir>o 

224 
2(X) 
240 
380 
305 
688 
370 


200 


FOODS   AND   DIETARIES 


Comparative  Nutritive  Values  and   Prices  of  Food  Materials  — 

Continued 


Sea  Foods  —  Continued 

Clams  in  shells    .     .     . 

Lobsters,  canned  .  . 
Oysters,  solids     .     .     . 

Dairy  Products 

Butter 

Cheese  ...... 

Eggs       *    .     . 

Milk,  whole  .  .  .  . 
Milk,  skimmed  .  .  . 
Milk,  condensed  .  . 
Cream 

Vegetables 

Beans,  green  .  .  .  . 
Beans,  baked  (canned) 
Beans,  dried   .     .     .     . 

Beets 

Cabbage     

Cauliflower     ,     .     .     . 

Celery 

Corn,  green  .  .  .  . 
Corn,  canned .     .     .     . 

Onions 

Parsnips 

Peas,  split 

Potatoes 

Potatoes,  sweet   .     .     . 

Pumpkins 

Squash 

Tomatoes,  canned    . 
Turnips 

Cereal  Products 

Barley 

Buckwheat      .     .     .     . 

Corn  meal 

Hominy 

Oatmeal  (in  pkgs.)  . 


Price 

PER 

Pound 
IN  Cents 

Ten  Cents  will 
Purchase 

Protein 
in  lbs. 

Fat  and 

Carbo. 

Energy 

Calories 

40 

.025 

79 

per  peck 
45 

.041 

135 

18 

.030 

130 

32 

.003 

1135 

21 

.096 

940 

23 

.058 

280 

4.5 

.072 

720 

3 

•  .102 

565 

12 

.073 

1260 

15 

.034 

1220 

4 

.102 

925 

15 

.045 

400 

7 

.320 

2580 

2 

.052 

840 

3 

.047 

415 

3 

.036 

465 

7 

.032 

250 

3 

.040 

600 

15 

.028 

455 

4 

.033 

515 

2 

.052 

1200 

7 

.351 

2515 

2 

.090 

1555 

3.5 

.035 

1085 

4 

.013 

150 

4 

.018 

265 

6 

.020 

175 

1.5 

.060 

835 

7 

.121 

2355 

G 

.069 

2770 

4 

.230 

4138 

5 

.166 

3300 

9 

.185 

2050 

PROBLKxM    173 


201 


Comparative  Nutritive  Values  and   Prices  of  Food   Materials  — 

Continued 


Cereal  Products  —  Continued 
Oatmeal  (in  bulk)    . 

Rice 

Flour,  graham     .     .     . 

Flour,  rye 

Flour,  entire  wheat 
Flour,  wheat  .... 
Bread,  white  .... 
Crackers,  soda     .     .     . 


Miscellaneous 
Cornstarch 

Molasses  .     . 

Olive  oil  .     . 

Sugar     .  . 

Tapioca  .     . 

Lard       .  .     . 

Sausage  .     . 

Fruits 

Apples  .     .     . 
Apples,  dried  . 
Apricots,  dried 
Bananas 
Berries  . 
Cherries     .     . 
Cranberries     . 
Dates     .     .     . 
Figs  .... 
Grapes  .     .     . 
Muskmelons  . 
Oranges 
Peaches 

Peaches,  canned 
Pears 

Pineapple  . 
Prunes  . 
Raisins  . 
Watermelons  . 


Price 

PER 

Pound 
IN  Cents 


G 
9 
4 
4 
5 
4 
G 
8 

8 
6 

70 
5 
9 

16 

22 

2 
18 
10 

8 

6 

6 

5 
12 
20 

4 

7 

6 

5 
10 

I 

10 
12. .• 

ir> 

4 


Te.n  Centh  will 
Pukcuabe 


Protein 
in  lbs. 


.278 
.089 

.170 
.275 
.285 
.154 
.134 


.060 

.021 
.010 
.047 
.096 
.(M)7 
.015 
.(K)S 
.016 
.022 
.025 
.005 
.014 
.020 
.008 
.015 
.(K)-l 
.014 
.015 


Fat  and 

Curbij. 

Eneiu;v 

Calories 


:W8.5 

1815 
4170 
4<)75 

:i;i.'>o 

4170 
2025 
23,S0 

1S50 
25S0 

(i05 
3756 
18.55 
2435 

965 

700 

7:>o 

121K) 
375 
290 
575 
430 
915 
715 
MO 
(>4() 
3«K) 
510 
255 
735 
2(K) 

9r>o 

1045 
150 


202 


FOODS   AND   DIETARIES 


Problem  1 7^ :  To  find  my  daily  Calorie  requirement. 
Method.  —  Use  the  following  tables  carefully. 

TABLE  1 

Daily  Calorie  Needs 

For  a  child  under  2  years 900  Calories 

For  a  child  from  2  to  5  years 1200  Calories 

For  a  child  from  6  to  9  years 1500  Calories 

For  a  child  from  10  to  12  years 1800  Calories 

For  girl  from  13  to  14  years  (woman,  light  work,  also)      .     2100  Calories 
For  boy  from  12  to  14,  girl  from  15  to  16  (man,  seden- 
tary)   2400  Calories 

For  boy  from  15  to  16  years  (man,  light  muscular  work)     2700  Calories 
For  man  (moderately  active  muscular  work)        ....     3000  Calories 

For  farmer  (busy  season) 3200  to  4000  Calories 

For  ditchers,  excavators,  etc 4000  to  5000  Calories 

For  lumbermen,  etc 5000  and  more  Calories 

Note.  —  According  to  Professor  Chittenden,  a  person  doing  moderate  work 
should  not  eat  more  than  /^  of  an  ounce  of  protein  for  each  pound  of  his  body  weight 
and  enough  fuel  foods  added  to  bring  the  total  up  to  between  2500  and  3000  Calories, 
This  is  a  good  general  rule  to  follow.  Still  another  check  on  your  daily  needs  when 
doing  light  work  may  be  obtained  by  multiplying  your  body  weight  by  16.1  Calories. 
The  result  will  be  approximately  your  daily  Calorie  requirement. 

But  the  body  needs  more  energy  when  it  works  hard.  The 
hourly  Calorie  requirement  is  shown  in  the  following  table. 

TABLE   2 

Hourly  Outgo  in  Heat  and  Energy  from  the  Human  Body  as  Deter- 
mined IN  the  Respiration  Calorimeter  by  the  United  States 
Department  of  Agriculture 

Average  (154  lb.)  Calories 

Resting    (asleep)       65 

Sitting  up  (awake) 100 

Light  exercise 170 

Moderate  exercise 290 

Severe  exercise 450 

Very  severe  exercise 600 

Observations.  —  Make  very  careful  observations  in  tabular 
form  giving  the  exact  Calorie  requirement  of  your  own  body,  us- 
ing first  the  age  requirement  (see  Table  1),  second  the  sex  require- 
ment (Table  1),  third  the  occupation  requirement  by  the  hourly 
standard  (see  Table  2).     Use  judgment  in  estimating  light  exer- 


PR0BLI<:M  175 


203 


ciso,  moderate  exercise,  and  severe  exercise.  No  })oy  or  ^irl  ifi 
high  school  ever  does  very  severe  exercise.  Li^lit  exercise  mi^ht 
be  taken  to  mean  walking;  to  school,  moving  about  the  house,  etc. 
Moderate  exercise  would  be  setting-uj)  thill,  walking  (not  running) 
upstairs,  or  any  exercise  that  will  cause  a  slight  perspiration. 
Severe  exercise  would  be  carrying  heavy  bundles,  football,  tennis, 
or  basket  ball  during  moments  of  active  play.  Use  considerable 
care  in  making  your  estimate  because  of  the  value  of  this  problem 
to  you. 

Conclusion.  —  1.  How  do  age,  weight,  occupation,  and  sex 
affect  your  daily  Calorie  requirement? 

2.  What  is  your  daily  Calorie  requirement? 

Problem  17^):  To  find  the  ]jro])ortion  of  protein,  fat,  and 
carbohydrate  needed  in  my  daily  Calorie  requirement. 

Materials.  —  Tables,  etc.,  in  tliis  volume  and  in  Hunter's  Civic 
Biology. 

NOTE.  —  At  least  three  different  investigators  have  slightly  different  beliefs  as 
to  just  what  this  proportion  of  protein,  fat,  and  carbohydrate  should  be;  but  all 
agree  in  one  detail,  that  the  proportion  of  protein  food  used  should  be  kept  low. 

The  following  table  gives  the  proportion  per  100  Calories  as 
given  by  At  water,  Chittenden,  and  Voit,  a  German  investigator. 


Atwater 
Chittenden 
Voit  .     .     . 


Cal.  from 
Protein 


14 
10 
25 


Cal.  from 
Fat 


32 

30 
20 


Cal.  from 
Carbohy- 
drate 


54 

m 

iJ5 


Of  the  three  given  above,  the  estimate  of  Chittenden  is  usually 
adopted  for  this  country  although  some  j)eople  believe  that  his 
proportion  of  protein  is  a  little  low.  Foods  taken  into  the  body 
having  these  proportions  of  the  nutrients  constitute  a  fnilanccd 
ration  or  dietary  because  they  provide  the  body  with  th(»  right 
proportion  for  tissue  building  as  well  as  for  fuel  food. 

Observations.  —  Compare  the  life  you  lead  with  that  of  a  day 
laborer.     Would  your  needs  be  the  same? 


204 


FOODS  AND   DIETARIES 


Compare  your  life  with  that  Uved  by  an  Eskimo  in  the  Arctic 
regions.  Would  the  proportion  of  the  nutrients  needed  by  him 
be  the  same  as  you  need?     Explain. 

Conclusion.  —  1.  Would  the  same  proportion  of  nutrients  be 
needed  in  all  localities? 

2.  Are  there  any  other  factors  that  might  cause  different  pro- 
portions of  the  nutrients  needed  by  individuals? 

Problem  170:  To  obtain  my  daily  dietary  witJi  the  100 
Calorie  table  of  Fisher  and  to  make  the  necessary  corrections 
in  my  dietary. 

Materials. —  Dr.  Irving  Fisher  of  Yale  University  has  worked 
out  the  following  tables  by  means  of  which  a  person  may  easily 
estimate  the  number  of  Calories  he  receives  from  any  given  food. 
The  use  of  these  tables  is  explained  in  the  laboratory  exercise  which 
follows. 

Table  of  100  Calorie  Portions  ^ 


Calories 

! 

Wt.  of 

Furnished 

BY 

TkT                                      T^ 

Portion  contain- 

100 

Name  of  Food 

ing  100  Food  Units 

Calo- 

(Approx.) 

ries 

(OZ.) 

Pro- 
tein 

Fat 

Car- 
bohy- 
drate 

Cooked  Meats 

Beef,  round,  boiled  (fat) . 

Small  serving   . 

1.3 

40 

60 

0 

Beef,  round,  boiled  (lean) 

Large  serving  . 

2.2 

90 

10 

0 

Beef,  round,  boiled  (med.) 

Small  serving   . 

1.6 

60 

40 

0 

Beef,  5th  rib,  roasted  . 

Half  serving     . 

.65 

12 

88 

0 

Beef,  ribs,  boiled     .     .     . 

Small  serving   . 

1.1 

27 

73 

0 

Chicken,  canned     .     .     . 

One  thin  slice  . 

.96 

23 

77 

0 

Lamb  chops,  broiled,  av.  . 

One  small  chop 

.96 

24 

76 

0 

Lamb,  leg,  roasted 

Ord.  serving     . 

1.8 

40 

60 

0 

Mutton,  leg,  boiled      .     . 

Large  serving  , 

1.2 

35 

65 

0 

Pork,  ham,  boiled  (fat)    . 

Small  serving   . 

.73 

14 

86 

0 

Pork,  ham,  roasted  (lean) 

Small  serving   . 

1.2 

33 

67 

0 

Turkey,     as     purchased. 

canned  

Small  serving   . 

.99 

23 

77 

0 

Veal,  leg,  boiled      .     .     . 

Large  serving  . 

2.4 

73 

27 

0 

^  These  tables  are  here  given  by  courtesy  of  The  Journal  of  the  American  Medical 
Association,  Vol.  XLVIII,  No.  16. 


PIIOBLEM    170 


205 


Table  of  100  Calohie  Poktions — Continued 


nT 

Calohie« 

I 

T^ 

Wt.  of 

FURNUHED 

BY 

FORTION    CONTAIN- 

100 

Name  of  Food 

ING  lOU  Food  Units 
(Appkox.) 

C'alo- 

HIKH 

IJ»,^ 

Car- 

(o».) 

1  rf>- 
tein 

Fat 

bohy- 
drate 

Uncooked     Meats,     Edible 

Portion 

Beef,  loin,  av.  (lean)    . 

Ord.  servmg 

1.8 

40 

60 

0 

Beef,     loin,     porterhouse 

steak,  av 

Small  steak 

1.3 

32 

68 

0 

Beef,  loin,  sirloin  steak,  av. 

Small  steak 

1.4 

31 

(J9 

0 

Beef,  ribs,  lean,  av.     .     . 

Ord.  serving 

1.8 

42 

58 

0 

Beef,  round,  lean,  av. 

Ord.  serving 

9  O 

.54 

46 

0 

Beef,  tongue,  av.     . 

Ord.  serving 

2.2 

47 

53 

0 

Beef,  juice 

Two  sm.  cups  . 

14 

78 

22 

0 

Chickens  (broilers),  av.    . 

Large  serving  . 

3.2 

79 

21 

0 

Clams,  round  in  shell,  av. 

12  to  16  .     .     . 

7.4 

56 

8 

36 

Cod  (whole) 

Two  servings    . 

4.9 

95 

5 

0 

Goose  (young)  av. .     .     . 

Half  serving 

.88 

16 

84 

0 

Halibut  steaks,  av. 

Ord.  serving 

2.8 

61 

39 

0 

Liver  (veal),  av. 

Two  sm.  servings 

2.8 

61 

39 

0 

Lobster  (whole),  a  v.    . 

Two  servings    . 

4.1 

78 

20 

2 

Mackerel  (Span.),  whole. 

av 

Ord.  serving 

2 

50 

50 

0 

Mutton,  leg,  hind,  lean,  av. 

Ord.  serving 

1.8 

41 

59 

0 

Oyster  in  shell,  av.      .     . 

One  dozen    .     . 

(j.8 

49 

22 

29 

Pork,  loin,  chops,  av. 

Very  sm.  serving 

.97 

18 

82 

0 

Pork,  ham,  lean,  av.    . 

Small  serving    . 

1.3 

29 

71 

0 

Pork,  bacon,  med.  fat,  av. 

Small  serving   . 

.53 

6 

94 

0 

Salmon  (Cal.),  av.       .     . 

Small  serving   . 

1.5 

30 

70 

0 

Shad,  whole,  av.     .     .     . 

Ord.  serving 

2.1 

46 

54 

0 

Turkey,  av 

Two  sm.  servings 

1.2 

29 

71 

0 

Vegetables 

Asparagus,  av.,  cooked    . 

Two  portions   . 

7.19 

18 

63 

19 

Beans,  baked,  canned 

Small  side  dish 

2.()() 

21 

IS 

()! 

Beans,  string,  cooked  . 

Five  servings    . 

10.66 

15 

48 

37 

Beets,      edible      portion. 

cooked        

Three  servings 

8.7 

23 

75 

Cabbage,  edible  portion  . 

Three  servings 

11 

20 

8 

72 

Carrots,  cooked       .     .     . 

Two  servings    . 

5.81 

10 

31 

:^K\ 

Cauliflower,  as  purchased 

11 

23 

15 

62 

Celery,  edible  portion 

Two  mod.  b'chs 

19 

24 

;> 

71 

Corn,  sweet,  cooked    . 

One  side  dish    . 

3.5 

13 

10 

i  1 

Cucumbers,  edible  portion 

Six  or  seven  serv. 

20 

IS 

10 

1  2 

Egg  plant,  edible  portion 

12 

17 

10 

73 

206 


FOODS   AND   DIETARIES 


Table  of  100  Calorie  Portions  —  Continued 


( 

[Calories 

Wt.  of 

Furnished 

BY 

XT                        .«           T^-rt..^  — 

Portion  contain- 

_  _  _    "1     f\f\           I  ,'  r~.    ,r-^  TT-— -.  _.  

100 
Calo- 

Name of  Food 

iNG  lUU  rooD  Units 

(Approx.) 

ries 

Pro- 
tein 

Car- 

(oz.) 

Fat 

bohy- 
drate 

Vegetables  —  Continued 

Lentils,  cooked  .... 

One  portion 

3.15 

27 

1 

72 

Lettuce,  edible  portion    . 

Two  sm.  heads 

18 

25 

14 

61 

Mushrooms,  as  purchased 

•          ••••• 

7.6 

31 

8 

61 

Onions,  cooked  .... 

Two  I'ge  servings 

8.4 

12 

40 

48 

Parsnips,  edible  portion  . 

One  half  serv.  . 

5.3 

10 

7 

83 

Peas,  green,  cooked     .     . 

One  ser\ang 

3 

23 

27 

50 

Potatoes,  baked      .     .     . 

One  good-sized 

3.05 

11 

1 

88 

Potatoes,  boiled      .     .     . 

One  large-sized 

3.62 

11 

1 

88 

Potatoes,  mashed 

(creamed) 

One  serving 

3.14 

10 

25 

65 

Potatoes,  chips        .     .     . 

One  half  serving 

.6 

4 

63 

33 

Potatoes,  sweet,  cooked  . 

Half  av.  potato 

1.7 

6 

9 

85 

Pumpkins,  edible  portion 

13 

15 

4 

81 

Radishes,  as  purchased    . 

17 

18 

3 

79 

Rhubarb,  edible  portion  . 

15 

10 

27 

63 

Spinach,  cooked      .     .     . 

Two  ord.  servings 

6.1 

15 

66 

19 

Squash,  edible  portion 

7.4 

12 

10 

78 

Succotash,  canned  .     . 

Ord.  serving     . 

3.5 

15 

9 

76 

Tomatoes,  fresh,  as  pur- 

chased         

Four  av.  servings 

15 

15 

16 

69 

Turnips,  edible  portion    . 

Two  I'ge  servings 

8.7 

13 

4 

83 

Fruits   (Dried) 

Apples,  as  purchased  .     . 

1.2 

3 

7 

90 

Apricots,  as  purchased     . 

1.24 

7 

3 

90 

Dates,  edible  portion  .     . 

Three  large .     . 

.99 

2 

7 

91 

Figs,  edible  portion     .     . 

One  large     .     . 

1.1 

5 

0 

95 

Prunes,  edible  portion 

Three  large .     . 

1.14 

3 

0 

97 

Raisins,  edible  portion     . 

1 

3 

9 

88 

Fruits  (Fresh  or  Cooked) 

Apples,  as  purchased  .     . 

Two  apples . 

7.3 

3 

7 

90 

Apples,  baked    .... 

One  serving 

3.3 

2 

5 

93 

Apples,  sauce     .... 

Ord.  serving 

3.9 

2 

5 

93 

Apricots,  cooked     .     .     . 

Large  serving  . 

4.61 

6 

0 

94 

Bananas,  edible  portion  . 

One  large 

3.5 

5 

5 

90 

Blackberries 

One  serving 

5.9 

9 

16 

75 

Blueberries 

One  serving 

4.6 

3 

8 

89 

Cantaloupe         .... 

Half  ord.  serving 

8.6 

6 

0 

94 

PROBLEM    17(i 


207 


Table  of  100  Caloiuk  Portiosh  —  Contimud 


Name  op  Food 


Fruits     {Fresh    or    Vooked) 
—  Continued 

Cherries,  edible  portion  . 
Cranberries,  as  purchased 
Grapes,  as  purchased,  av. 

Grapefruit 

Grape  juice 

Gooseberries       .... 

Lemons 

Olives,  ripe 

Oranges,  as  purqhased,  av. 
Oranges,  juice    .... 
Peaches,  as  purchased,  av. 
Peaches,  sauce  .... 

Pineapples,  edible  portion, 
av 

Raspberries,  red  .  . 
Strawberries,  av.  .  . 
Watermelon,  av.     .     .     . 


PonnON    CONTAIN- 
ING 100  Food  I'nits 
(Approx.) 


Small  dish  . 


Small  bunch 
Half  .  .  . 
Small  glass  . 

About  two  . 
About  seven 
One  very  large 
Large  glass  . 
Three  ordinary 
Ord.  serving 
One  large     . 

One  serving 
One  serving 
Two  servings 


Dairy  Products 

Butter       .     .     . 
Buttermilk     . 
Cheese,  Am.  pale 
Cheese,  cottage 
Cheese,  cream    . 
Cheese,  Swiss 
Cream 

Milk  condensed,  sweetened 
Milk,  condensed,  un- 
sweetened   

Milk,  whole 

Cakes,     Pastry,     Puddings, 
and  Desserts 

Cake,  chocolate  layer 
Cake,  gingerbread  .     .     . 
Cake,  sponge      .... 
Custard,  milk     .... 


1  pat 


1^  glasses 
1^  cubic  in. 

4  cubic  in. 
1|  cubic  in. 
1^  cubic  in. 
2  ord.  glass. 

5  cup  .     . 


t  cup  .     . 
Small  glass 


J  ord.  sq.  piece 
2  ord.  sq.  piece 
Small  piece  . 
Ord.  cup 


Wt.  of 

100 
Calo- 

KIEH 
(02.) 


C\ljOHlF.tt 
FuilNiaUED   BY 


4.4 

7.5 
4.8 
7.57 
4.2 
9.2 
7.57 
1.31 
9.4 
().G2 
10 
4.78 
5.40 

8 

G.29 
9.1 
27 


.44 
9.7 

.77 
3.12 

.82 

.8 
1.7 
1.0() 

2.05 
4.9 


.98 

.90 

.89 

4.29 


I'ro- 

tein 


5 
3 

5 

7 
0 


9 

0 
0 
7 
4 
4 

4 

8 

10 

0 


.5 


34 
25 
76 
25 
25 
5 
1(1 

24 
19 


2(3 


Fat 


10 
12 
15 

4 

0 

0 

14 

91 

3 

0 
') 

2 

7 

G 

0 

15 

0 


99.5 

12 

73 

8 
73 
71 
8() 

23 

50 
52 


22 
23 
25 
5(i 


Car- 
bohy- 
drate 


85 
85 
80 

89 

\m 

95 
77 
7 
91 
100 
91 
94 
89 

90 
92 
75 

88 


0 

54 

2 

If) 
2 

1 

9 

67 

26 
29 


71 
71 
68 
18 


208 


FOODS   AND    DIETARIES 


Table  of  100  Calorie  Portions — Continued 


Calories 

Wt.  of 

Fu 

RNISHED 

BY 

Portion  contain- 

__ _  _.      1  i\f\     T^  ,r^  ,f~^ T T _,^ 

100 

Name  of  Food 

ING    100   l^OOD    UNITS 

Calo- 

1 

(Approx.) 

ries 

Pro- 
tein 

1 

Car- 

(oz.) 

Fat 

bohy- 
drate 

Cakes,  Pastry,  Puddings, and 

Desserts  —  Continued 

Custard,  tapioca     . 

Two  thirds  ord. 

2.45 

9 

12 

79 

Doughnuts     .     .     . 

Half  a  doughnut 

.8 

6 

45 

49 

Lady  fingers 

Two  to  three    . 

.95 

10 

12 

78 

Macaroons 

Two  to  three    . 

.82 

6 

33 

61 

Pie,  apple 

One  third  piece 

1.3 

5 

32 

63 

Pie,  cream 

One  fourth  piece 

1.1 

5 

32 

63 

Pie,  custard 

One  third  piece 

1.9 

9 

32 

59 

Pie,  lemon 

One  third  piece 

1.35 

6 

36 

58 

Pie,  mince 

One  fourth  piece 

1.2 

8 

38 

54 

Pie,  squash 

One  third  piece 

1.9 

lb 

42 

48 

Pudding,  apple  sago 

One  serving 

3.02 

6 

3 

91 

Pudding,  cream  rice 

Very  small  serv- 

ing .     .     .     . 

2.65 

8 

13 

79 

Pudding,  Indian  meal 

HalP  ord.  serving 

2 

12 

25 

63 

Pudding,  apple  tapioca    . 

Small  serving    . 

2.8 

1 

1 

98 

Tapioca,  cooked 

Ord.  serving     . 

3.85 

1 

1 

98 

Sweets  and  Pickles 

Catsup,  tomato,  av.    .     . 

i  qt.  bottle  .     . 

6 

10 

3 

87 

Honey 

Pour  teaspoons 

1.05 

1 

0 

99 

Marmalade,  orange     .     . 

Four  teaspoons 

1 

.5 

2.5 

97 

Molasses,  cane  .... 

Four  teaspoons 

1.2 

.5 

0 

99.5 

Olives,       green,       edible 

portion 

Seven  olives 

1.1 

1 

84 

15 

Pickles,  mixed         .     . 

14.6 

18 

15 

67 

Sugar,  granulated  .     .     . 

Three   teaspoons 

or  1|  lumps    . 

.86 

0 

0 

100 

Sirup,  maple       .... 

Four  teaspoons 

1.2 

0 

0 

100 

Nuts,  Edible  Portion 

Almonds,  av 

Eight  to  fifteen 

.53 

13 

77 

10 

Brazil  nuts 

Three  ord.  size 

.49 

10 

86 

4 

Butternuts 

About  six     .     . 

.50 

16 

82 

2 

Coconuts        

.57 

4 

77 

19 

Chestnuts,  fresh,  av.  ,     . 

i  of  a  cup    .     . 

1.4 

10 

20 

70 

Filberts,  av 

Ten  nuts 

.48 

9 

84 

7 

Hickory  nuts      .... 

About  ten    .     . 

.47 

9 

85 

6 

Peanuts     

Thirteen,  double 

.62 

20 

63 

17 

PROBLEM    170 


200 


Table  of  1(K)  Calorie  Portionh—  Continued 


Name  of  Food 


Nuts,  Edible  Portion  —  Con- 
tinued 

Pecans,  polished 
Pine  nuts  (pignolias)  . 
Walnuts,  California     . 

Cereals 

Bread,  brown,  av.  . 
Bread,  corn  (johnnycake) 

av 

Bread,  white,  homemade 
Corn  flakes,  toasted    . 
Corn  meal,  ^anular,  av 
Crackers,  graham 
Crackers,  oatmeal 
Hominy,  cooked 
Macaroni,  cooked 
Oatmeal,  boiled 
Popcorn    .     .     . 
Rice,  boiled  . 
Rice,  flakes    . 
Rolls,  Vienna,  av. 
Shredded  wheat 
Spaghetti,  av.     . 
Zwieback  .     .     . 


Portion  contain- 
ing 100  Food  Units 
(Approx.) 


Miscellaneous 

Eggs,  hen's,  boiled 
Eggs,  hen's,  whites 
Eggs,  hen's,  yolks  . 
Omelet      .     . 
Soup,  beef,  av. 
Soup,  bean,  av 
Soup,  cream  of  celery 
Consomme     . 
Clam  chowder 
Chocolate,  bitter 
Cocoa  . 
Ice  cream  . 


About  eight 
About  eighty 
About  six     . 


Ord.  thick  slice 

Small  square  . 
Ord.  thick  sHce 
Ord.  cereal  dish 


Two  crackers 
Two  crackers 
Large  serving 
Ord.  serving 
1^  serving    . 


Ord.  cereal  dish 
Ord.  cereal  dish 
One  largo  roll   . 
One  biscuit  . 
One  serving 
Size  of  thick  slice 
of  bread    . 

One  large  eg^  . 
Two  whites 
Two  yolks    . 
Small  serving   . 
2.}  plates       .     . 
Very  large  plate 
Two  phitcs  . 
Five  to  six  cups 
Two  plates  . 
Half  a  square   . 
J  of  5  ff  cake 
Small  brick. 


Wt.  op 
100 

Calo- 
ries 
(oz.) 


Cai.oriks 
fuh.nihhed  by 


.40 
.50 

AS 


Lr> 

L3 
L3 

.97 

.90 

.82 

.81 

4.2 

3.85 

5.0 

.80 
3.1 

.94 
1.2 
.94 
.97 

.81 

2.1 

0.4 
.94 

3.3 
13 

5.4 

0.3 
29 

8.25 
.50 
.()9 

l.() 


Pro- 
tein 


0 
22 

10 


9 

12 
13 
11 
10 

9 
11 
11 
14 
18 
11 
10 

8 
12 
13 
12 

9 

32 

1(H) 
17 
34 
09 
20 

ir. 

85 
17 

8 
17 

5 


Fat 


87 
74 
S3 


10 
0 
1 
5 

20 

24 
2 

15 

7 
11 

1 

1 

/ 

4. 

1 

21 

OS 
0 

(K) 
14 
10 
47 
0 
18 
72 
53 
()2 


Car- 
bohy- 
drate 


7 
4 

7 


84 

72 
81 

88 
85 
71 
05 
87 
71 

/.) 

78 

89 

91 

81 

82.5 

87 

70 

0 

0 

0 

0 
17 
70 
37 
15 
65 
20 
30 
33 


HUNTER  LAB.  PROB.  —  14 


210 


FOODS   AND   DIETARIES 


NOTE.  —  Should  you  desire  to  add  further  items  to  the  prccodiug  tabic,  obtain 
Experiment  Station  Bulletin  28,  The  Chemical  Composition  of  American  Food 
Materials,  by  Atwater  and  Bryant.  (Send  10  cents  in  coin  to  Superintendent  of 
Documents,  Washington,  D.C.)  The  weight  in  ounces  of  a  standard  portion  equals 
1600  divided  by  number  of  Calories  per  pound  given  in  table.  The  Calories  fur- 
nished by  protein  equal  the  percentage  of  protein  given  in  the  Bulletin  table  mul- 
tiplied by  1860  and  divided  by  the  number  of  Calories  per  pound.  The  same  cal- 
culation and  factor  applies  to  carbohydrates.  For  fat,  calculate  the  same  way, 
but  use  the  factor  4220  in  place  of  1860.  Verify  the  three  results  by  adding  to  see 
if  they  equal  100  Calories. 


Daily  Dietary  of  a  First  Term  High  School  Boy 


Calories 

Protein 

Fat 

Carbohy- 
drate 

Total 

Breakfast 

Orange   

Hominy  (a  small  serving) . 

Avitli  milk  3  oz.  and,     . 

sugar  (3  teaspoonfuls)     . 
Toast,  2  slices 

with  butter 

One  boiled  Qgg 

Coffee,  cream,  and  sugar  .     . 

6 

8 
9 

3 

.5 
32 
1 

3 

1 
26 

1 
66 
68 

28 

91 
67 
15 
100 
15 

70 

Lunch 

Cream  of  corn  soup       .     . 
Soda  crackers  (3)      ... 
Bread,  2  slices      .... 
Butter,  1  pat 

59.5 

11 
15 
26 
.4 
5 
26 

193 

58 
30 
12 
75 

56 

358 

31 
105 
162 

162 

18 

610.5 

Prunes,  5  large     .... 
Cup  of  milk  custard      .     . 

Dinner 

Boiled  mutton      .... 
Two  baked  potatoes      .     . 
Brown  gravy  .... 

83.4 

35 
22 

3 
10 

.3 
15 

1 

15 

231 

65 
2 

68 
4 

60 

66 

42 

478 

176 

8 

60 

19 
136 

40 
153 

792.4 

Bread  (a  thin  slice)  .     . 
Butter 

Spinach  (large  serving) 
Pineapple  (canned)  .     . 
with  juice   .... 
Molasses  cookies       .     . 

101.3 

307 

592 

1000.3 

Total  day's  dietary  = 


2403.2  Cal. 


PROBLEM    178  211 

Method.  —  First  make  careful  note  of  all  food  that  enters  your 
body  during  24  hours.  Not  only  the  amount  taken  at  meals,  hut 
all  between  meals,  should  be  noted.  Usin<z;  the  tables,  arrange 
your  data  according  to  the  preceding  example. 

You  already  know  your  Calorie  requirement  from  a  previous 
experiment.  You  know  the  proportion  of  Calories  you  need  of 
protein,  fat,  and  carbohydrate  according  to  Atwater,  Chitten- 
den, and  Voit.  You  have  now  worked  out  the  actual  proportion 
in  your  daily  food  income  as  shown  by  the  100-Calorie  portion. 

Conclusion.  —  1.  Am  I  eating  the  right  proportion  of  protein, 
fat,  and  carbohydrate  according  to  the  standard  of  (a)  Atwater, 
(6)  Chittenden,  (c)  Voit?  (Ask  your  instructor  whicli  of  the 
above  standards  you  should  follow.) 

2.  What  can  I  do  to  make  my  dietary  more  suited  to  my  needs? 

Problem  177 :  To  coi7V])are  your  (Jay'fi  total  Cal or'us  irifJi  the 
estimated  needs  of  a  person  of  your  a^e  doing  the  kind  of 
worlc  which  you  do. 

Method.  —  Check  up  your  day's  total  Calories  by  comparing 
it  with  your  requirement  by  body  weight  and  by  Tables  1  and  2, 
Problem  174. 

Head  your  paper  :  Name ,  age ,  weight lbs. 

Daily  Calorie  needs 

Amount  computed 

Discrepancy 


Conclusion.  —  1.  How  does  your  day's  total  Calories  compare 
with  that  given  in  the  table  of  daily  needs  of  a  jierson  of  your  age. 
doing  the  kind  of  work  you  did  for  the  day  ? 

2.  If  there  is  any  discrepancy,  liow  can  you  account  for  it  ? 

3.  Can  you  suggest  any  improvement  in  your  dietary? 

rrohlem  J7S:  To  find  the  relation  of  the  value  of  food  to  its 
cost  in  tJie  famihj  dietary. 

Method.  —  Make  a  careful  i-c^-ord  of  all  i)Ui<-hases  of  food  in 
your  home  for  one  week.  Find  oul  what  tlu^  average  weekly 
cost  is  by  dividing  the  total  cost  by  the  number  in  your  family. 


212  FOODS  AND   DIETARIES 

Using  the  table  on  pages  198  to  201  and  your  daily  Calorie 
requirement,  make  out  a  cheap  but  well-balanced  ration  for  one 
person  for  a  period  of  one  week.  Multiply  the  result  by  the  total 
number  in  your  family.  Compare  the  total  cost  thus  obtained 
with  that  worked  out  from  your  home  dietary. 

Conclusion.  —  1.    Are  you  living  as  cheaply  as  you  might? 

2.  What  inexpensive  substitutes  might  you  introduce  in  place 
of  meat? 

Problem  1 79 :  To  study  some  forms  of  food  adulteration  and 
some  means  of  detecting  adulterants. 

NOTE.  —  Foods  are  said  to  be  adulterated  when  any  substance  is  added  to 
them  to  cheapen  their  cost.  Such  added  materials  are  not  of  necessity  unwhole- 
some ;  for  example,  starch  is  added  to  sausage  to  enable  the  seller  to  make  a  larger 
profit.  Some  adulterants  are  chemical  preservatives ;  for  example,  boric  acid, 
borax,  benzoate  of  soda,  formaldehyde,  and  sulphurous  acid.  Others  are  coloring 
matters.  They  are  used  in  cheaper  grades  of  jelly,  tomato  catsup,  canned  toma- 
toes, pickles,  peas,  and  beans  (a  copper  salt  is  used  to  make  them  greener),  and 
butter  of  a  poor  grade  is  made  to  look  yellow,  etc.  Certain  common  frauds  are 
easily  detected  by  the  tests  which  follow. 

a.  Test  for  Pure  Butter 

Materials.  —  Butter,  spoon. 

Method.  —  Put  some  butter  in  a  spoon  and  heat  it  over  a  lamp. 
If  it  is  good  butter,  it  will  boil  quietly  with  much  foam.  Oleo- 
margarine or  poor  butter  will  splutter  and  crackle  with  little  foam. 

Observations.  —  How  does  the  butter  act  when  heated? 

Conclusion.  —  Is  the  butter  tested  pure? 

b.  Test  for  Adulteration  in  Coffee 

Materials.  —  Ground  coffee,  beaker. 

Method.  —  Place  half  a  teaspoonful  of  coffee  to  be  tested  on 
the  surface  of  a  glass  of  cold  water.  Leave  it  for  not  more  than 
five  minutes. 

Observations.  —  If  the  material  sinks,  leaving  a  brownish  trace 
in  the  water  as  it  sinks,  it  is  chicory.  If  it  floats  for  five  min- 
utes, it  is  coffee.     What  happens? 

Conclusion.  —  Is  the  coffee  tested  pure  coffee? 


PROBLE.M    ISO  2i:i 

c.   Test  for  Copper 

Materials.  —  Canned  peas  or  beans,  beaker,  hydrochloric  acid, 
iron  nail. 

Method.  —  Place  half  a  spoonful  of  niashed  canned  peas  or 
beans  in  a  beaker  containing  one  spoonful  of  water  and  10  drops 
of  hydrochloric  acid.  Set  the  beaker  in  a  dish  of  boihng  water. 
Drop  a  new  iron  nail  into  the  mixture.  Boil  for  ten  minutes. 
Stir  constantly. 

Observations.  —  What  color  does  the  nail  turn  ?    (See  note,  jiage 

212.) 

Conclusion.  —  Is  copper  present  in  the  material  tested? 

d.   Are  Eggs  Fresh? 

Materials.  —  Egg,  salt  solution. 

Method.  —  Make  a  weak  (10  per  cent)  salt  solution.  Place 
eggs  to  be  tested  in  the  solution. 

Observations.  —  Do  the  eggs  you  test  float?  If  so,  they  are 
fresh. 

Conclusion.  —  Are  the  eggs  tested  fresh? 

e.   To  Test  Milk  for  Formaldehyde 
Note.  —  Formaldehyde  is  an  unlawful  adulterant. 

Materials.  —  Milk,  beaker,  hydrochloric  acid,  ferric  chloride. 

Method,  —  Put  in  a  beaker  a  teaspoonful  of  milk  from  t  he  dairy 
that  supplies  your  home  or  lunch  room.  Add  twice  the  amount 
of  hydrochloric  acid  to  which  a  drop  of  ferric  chloride  has  been 
added.  Mix  by  rotating  the  beaker  gently.  Place  the  beaker  in 
a  pan  of  boiling  water  and  leave  for  5  minutes. 

Observations.  —  If  there  is  a  purple  or  lavender  color,  formalde- 
hyde was  present  in  the  milk. 

Conclusion.  —  Is  formaldehyde  present  in  the  milk  t(^sted'.* 

Prohleni  ISO:  To  (leteri)iliie  tJie  effrcf  of  dlcohol  nftntt  raw 
white  of  egg. 

Materials.  —  White  of  egg,  alcohol,  test  tubes. 

NOTE.  —  In  chemical  and  physical  composition  the  whito  of  crr  i.«<  nearly 
like  protoplasm. 


214 


FOODS   AND   DIETARIES 


Method  and  Observations.  —  Fill  a  test  tube  with  raw  white  of 
egg.  Pour  slowly  a  little  alcohol  into  the  tube.  What  effect  does 
it  have  on  the  white  of  egg?  Pour  in  equal  amounts  of  alcohol  and 
of  egg,  and  mix  the  two  substances  by  shaking.  What  is  the 
effect  ? 

NOTE.  —  The  alcohol  takes  out  the  water  from  the  white  of  egg. 

Conclusion.  —  What  does  alcohol  do  to  white  of  egg?  Might 
it  have  the  same  effect  upon  living  matter? 

Problem  ISl :  To  deterinine  the  ainount  of  alcohol  in  some 
patent  inedicines. 

Materials.  —  Materials  shown  in  cut  in  Civic  Biology,  page  294. 
Observations.  —  Note  the  percentage  of  alcohol  (represented  by 

the  solid  black)  in  the 


test    tubes.       A    test 

tube  represents  a  glass. 

Compare  the  amount 

of    alcohol    in   bitters 

(A)  as  compared  with  a 

like   amount   of  beer. 

Compare  the  amount 

of  alcohol  in  tonic  {j)  as 

compared  with  a  like 

amount  of  champagne. 

Many  Indians,  when  the  sale  of  liquor  was  stopped  on  their 

reservation,  began   using  certain   patent  remedies.     How  many 

glasses  of  bitters  {k)  would  they  have  to  take  to  get  the  amount  of 

alcohol  found  in  a  glass  of  whisky? 

Conclusion.  —  1.  Why  are  some  patent  medicines  dangerous? 
2.  Why  might  they  have  a  tonic  effect? 

Problem  182 :  To  test  for  acetanilid  and  to  hnow  some  patent 
medicines  containing  it. 

Materials.  —  Headache  powder,  zinc  chloride,  test  tube. 

Method.  —  Mix  a  half  spoonful  of  zinc  chloride  with  an  equal 
amount  of  some  headache  powder  in  a  dry  test  tube.  Heat 
slowly. 


PROBLEM    183  21.-) 

Observations.  —  Note  the  funios.  Place  a  match  or  })it  of  wood 
in  the  fumes.  If  the  wood  is  colored  red  or  yellow,  then  the  medi- 
cine contains  the  dangerous  heart  depressant  drug  called  acetan- 
ilid. 

Conclusion.  —  1.  How  would  you  know  the  presence  of  acet- 
anilid  in  a  substance? 

2.  Why  would  samples  of  medicines  containing  acetanilid  l)e 
distributed  free? 

3.  Why  are  such  medicines  unsafe  to  use? 

Proble^n  183:  Wliat  are  the  harmful  materials  formed  iti 
catarrh  cures  and  soothing  sirups  ? 

Materials.  —  Charts,  labels  of  soothing  sirups  and  catarrh 
cures. 

Method.  —  Using  the  charts  made  by  the  American  Medical 
Association,^  535  N.  Dearborn  St.,  Chicago,  111.,  Farmers'  Bulletin 
393,  and  the  labels  of  various  soothing  sirups  and  catarrh  cures, 
determine  which  ones  contain  opium,  cocaine,  morphine,  codine, 
or  other  habit-forming  drugs. 

NOTE.  —  Many  of  the  so-called  catarrh  cures  or  soothing  sirups  owe  thoir 
eflBcacy  to  some  of  the  above-mentioned  drugs.  The  Pure  Food  and  Drug  Law 
requires  that  the  labels  of  patent  medicines  tell  all  the  ingredients  therein  contained. 

Observations.  —  How^  many  of  the  medicines  examined  con- 
tained habit-forming  drugs?  What  kind  of  newsj)apers  in  your 
city  carry  advertisements  of  any  of  the  above  medicines?  Do 
these  papers  bear  a  good  reputation? 

Conclusion.  —  1.  W^hy  would  working  girls  be  likely  to  use 
catarrh  cures? 

2.  Why  do  mothers  give  babies  soothing  sirup?  What  might 
be  the  effect  on  the  child? 

3.  What  would  be  the  efTect  upon  any  one  who  took  such  drugs 
frequently  ? 

1  The  Great  American  Fraud,  by  S.  H.  Adam.'^,  reprinted  by  the.VmericMM  .Medi- 
cal Association,  has  been  the  basis  from  whidi  were  made  Problems  181,  1S2.  and 
183.  Other  problems  of  equal  value  on  Preying  on  the  Incurahlr,  The  Surecure 
Remedies,  The  Specialist  Humbug,  and  The  Scavengers  may  \io  obtained  from  tluH 
source  and  are  reconnnended  if  time  permits.  Work  of  this  .sort  is  certainly  pra«-ti- 
cal,  interesting,  and  worth  while, 


216 


FOODS   AND   DIETARIES 


Problem  Questions 

1.  What  is  a  nutrient?     What  uses  have  nutrients  in  foods? 

2.  What  are  the  differences  between  a  food  and  a  nutrient? 

3.  What  is  a  balanced  ration? 

4.  What  differences  should  age,  sex,  occupation,  environment, 
and  health  make  in  a  daily  dietary? 

5.  Why  should  foods  be  cooked?     Give  three  reasons. 

6.  What  is  a  Calorie? 

7.  Why  is  a  mixed  diet  necessary  ? 

8.  Name  five  common  errors  in  eating. 

9.  Of  what  use  are  inorganic  nutrients? 

10.  Of  what  use  are  condiments  and  flavoring  substances? 

11.  How  do  vegetable  foods  compare  in  nutritive  value  with 
animal  foods? 

12.  How  do  vegetable  foods  compare  in  cost  with  animal  foods? 

13.  How  do  beans  and  peas  compare  with  meats  as  to  cost  and 
protein  content? 

14.  How  does  fish  compare  with  meat  as  to  cost  and  protein 
content? 

15.  How  do  eggs  and  milk  compare  with  meat  as  foods?  How 
do  they  compare  in  cost? 

16.  How  do  nuts  compare  with  meat  in  cost  as  a  source  of 
protein  ? 

17.  Compare  poultry  with  meat  as  to  cost  and  protein  content. 

18.  Compare  cheese  with  meat  in  price  and  protein  content. 

19.  Would  a  vegetarian  diet  be  possible  from  the  standpoint 
of  protein  necessary  to  the  body?  How  would  it  compare  with 
a  diet  containing  meat?  Are  there  any  reasons  why  a  vegetable 
diet  is  unwise? 

20.  Of  what  use  are  soups  as  food  ? 

21.  Why  do  we  use  fruit  in  a  daily  dietary? 

22.  Is  the  use  of  tea,  coffee,  or  cocoa  justifiable  in  a  daily  diet? 
Why  do  people  drink  them? 

23.  Why  are  cheap  cuts  of  meat  cheap? 

24.  Defend  the  statement,  "  The  average  American  family 
wastes  enough  in  the  kitchen  to  support  a  French  family." 


REFERENCE   BOOKS  217 

25.  Is  alcohol  a  food?  Is  it  a  poison?  Can  any  material  be 
both  a  food  and  a  poison  ? 

26.  Do  you  know  the  pure  food  laws  of  your  state?  If  not, 
procure  a  copy  and  learn  them. 

27.  What  is  wrong  with  our  present  Federal  Pure  Food  and 
Drug  Law? 

28.  What  is  an  adulteration?  Does  your  jiure  food  hiw  pro- 
tect you  from  adulteration  of  food? 

Reports  for  home  work  are  recommended  in  the  work  of  this  chapter.  In  this 
connection,  the  reports  of  the  Department  of  Agriculture  on  various  food  topics  are 
recommended.    See  the  list  of  reference  books  which  follows. 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XIX.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chap.  XXVII.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XXIV.     American  Book  Company. 

Abel,  Beans,  Peas,  and  Other  Legumes  as  Food.     Bulletin  121,  U.  S.  Department 

of  Agriculture. 
Abel,  Practical  Sanitary  and  Economic  Cooking.     Public  Health  Association. 
Abel,  The  Care  of  Food  in  the  Home.     Farmers'  Bulletin  375,  U.  S.  Department  of 

Agriculture,  1909. 
Adams,  The  Great  American  Fraud.     American  Medical  Association,  Chicago,  111. 
Allen,  Civics  and  Health.     Ginn  and  Company. 
AUyn,  Libel  on  Eggs.     Harper's  Weekly,  August  29,  1914. 
Atwater,  Bread  and  Bread  Making.     Farmers'  Bulletin  389,  U.  S.  Department  of 

Agriculture. 
Atwater,  Billings,   Bowdich,  Chittenden,  and  Welch,  Physiological  Aspect  of  the 

Liquor  Problem.     Houghton  Mifflin  Company. 
Atwater   and    Bryant,    The   Chemical   Composition   of  American   Food   Materials. 

Experiment  Station  Bulletin  28,  Washington,  D.C. 
Bardswell  and  Chapman,  Diets  in  Tuberculosis.     Oxford  University  Press. 
Benson,  Facts  About  the  Food  Problem.     Pearson's  Magazine,  April,  1910. 
Bevier  and  Van  Meter,  Selection  and  Preparation  of  Food.     Whitcomb  and  Barrows. 
Capes,  Duty  of  Municipal  Food  Inspection.     .Atnerican  City,  February.  1914. 
Cereal  Breakfast  Foods.      Farmers'  Bulletin  249,  U.  S.    Depnrtnient   of  .Vgriculturo. 
Course  in  Cereal  Foods  and  their  Preparation.      Bulletin  200,  Olfirc  of  Experiment 

Station,  Washington,  D.C. 
Davenport,  Why  Food  is  Costly,     (lood  Housekeeping  Mngazint\  April,  1910. 
Day,  Digestibility  of  Starch  as  Affected  by  Cooking.     Bulletin  202.  Office  of  Kxi>cri- 

ment  Station,  Washington,  D.C. 
Eggs  and  their  Uses  as  Food.     Farmers'   Bulletin   12S.  V.  S.  Dep.-irtmcnt  of  Agri- 
culture, 1906. 
Fdcis  about  Milk.      Farmers'  Bulletin  42,  U.  S.  Department  of  AKri<ullure.  lUOii. 
/'/.s//  as  Food.      Farmers'  Bulletin  85,  U.  S.  Department  <>f  .Vgricultun'.  1907. 
Fisher,  Food  Values.     Bulletin  13,  American  School  of  Home  Economics,  Chicago. 


218 


FOODS   AND   DIETARIES 


Food  and  Diet  in  the  United  States.     Yearbook,  U.  S.  Department  of  Agriculture. 

Food  Value  of  Fruits.     Review  of  Reviews,  September,  1914. 

Foods,  Nutritive  Value  and  Cost.     Farmers'    Bulletin    23,    U.    S.    Department   of 

Agriculture. 
Forbes,  What  Not  to  Do  For  a  Headache.     World's  Work,  June,  1910. 
Fruit  and  its  Uses  as  Food.     Yearbook  Reprint. 

Hendrick,  Farce  of  Pure  Food  Law.     McClure's  Magazine,  August,  1914. 
Hopkins,  Bread  from  Stones.     Country  Life,  March,  1914. 
Howard,  The  Use  of  the  Microscope  in  Food  Adulteration.      Separate  455,  Yearbook 

U.  S.  Department  of  Agriculture,'  1907. 
Hunt,  The  Daily  Meals  of  School  Children.     Bulletin  3,  U.  S.  Bureau  of  Education, 

1909. 
Hutchinson,  Applied  Physiology.     Edward  Arnold. 
Influence  of  Food  Preservatives  and  Artificial  Colors  on  Food.     Chemical  Bulletin  84, 

Parts  2,  3,  U.  S.  Department  of  Agriculture. 
Johnson,  The  Drug  Clerk  a  Poor  Doctor.     World's  Work,  July,  1910. 
Journal  of  Home  Economics.     American  Home  Economics  Association. 
Kebler  and  others,  Harmfulness  of  Headache  Mixtures.     Farmers'   Bulletin  377, 

U.  S.  Department  of  Agriculture. 
Kellogg,  Battle  Creek  Sanatarium  Diet  List.    Good  Health  Publishing  Company, 

Battle  Creek,  Mich. 
Langworthy,  Functions  and  Uses  of  Food.     Experiment  Station  Circular  46. 
Loaf  of  Bread.     Scientific  American,  April  25,  1914. 
McGill,  Infants'  and  Invalids'  Foods.     Bulletin  185,  Inland  Revenue  Department, 

Ottawa,  February,  1910. 
Medical  Fakes  and  Fakers  (pamphlets  on) .    American  Medical  Association,  Chicago, 

lU. 
Milk  as  Food.     Farmers'  Bulletin  74,  U.  S.  Department  of  Agriculture,  1904. 
Milner,  The  Cost  of  Food  as  Related  to  its  Nutritive  Value.     Reprint  from  Yearbook, 

U.  S.  Department  of  Agriculture,  1902. 
Milner,  The  Use  of  Milk  as  Food.     Farmers'   Bulletin  363,   U.  S.  Department  of 

Agriculture. 
Mitchell,  A  Course  in  Cereal  Foods  and  their  Preparation.    Bulletin  200,  Agricultural 

Experiment  Station,  Washington,  D.C. 
Moore,  Oysters  and  Methods  of  Oyster  Culture.     Report  U.   S.  Fish  Commission, 

1897. 
Norton,  Food  and  Dietetics.     American  School  of  Home  Economics,  Chicago,  1907. 
Nostrums  and  Quackery.     American  Medical  Association,  Chicago,  III. 
Patrick,  Household  Tests  for  the  Detection  of  Oleomargarine  and  Renovated  Butter. 

Farmers'  Bulletin  131,  U.  S.  Department  of  Agriculture,  1901. 
Pope  and  Carpenter,  Essentials  of  Dietetics.     G.  P.  Putnam  and  Sons. 
Protection  of  Food  Products  from  Injurious  Temperatures.     Farmers'  Bulletin  125, 

U.  S.  Department  of  Agriculture. 
Purdy,  Foods  which  Make  Energy.     Delineator,  June,  1914. 
Pure  Food  Laws.     Survey,  May  23,  1914. 
Rensselaer,  Food  for  the  Farmers'   Family.     Cornell    University   Reading   Course, 

Series  III,  No.  14,  1905. 
Retail  Prices  of  Food,   1890-1907.     Bulletin  77,   U.   S.   Bureau  of  Labor,    1908, 

Washington,  D.C, 


refi:rence  j^ooks  219 

Rorer,  Correct  Combinations  of  Foods.     Good  Housekeeping,  May.   11)1  I. 
Russell,  The  Danger  in  the  Drug  Store.     Pearson's  Magazine,  June,   IIUO. 
Sinitli,  Deleterious  Ingredients  in  Foods,     l^cience,  February,  1010. 
Snyder,  Human  Foods.     The  Maenullan  f 'oinpauy. 

Sugar  as  Food.      Fanners'  Bulletin  9.3,  U.  S.  Department  of  Aurieulture,  I'JUO. 
Thompson,  Diet.     Frederick  Warne  and  ('ompany,  London.  1*.K)2. 
Weyl,  Pure  Milk  and  Human  Life.     Success  Magazine,  March,  1!M)',). 
Wiley,  Foods  and  their  Adulteration.     P.  Blakiston'.s  Son  and  Company. 
Williams,  Factors  of  Bread  Making.     Home  Economics,  February.  1914. 


XX.   DIGESTION   AND   ABSORPTION 

Problems.  —  To  determine  where  digestion  tahes  place  by  ex- 
amining :— 

(a)  Til  e  functions  of  glands. 

(b)  The  work  done  in  the  mouth. 

(c)  The  ivorh  done  in  the  stomach. 

(d)  The  worh  done  in  the  small  intestine. 

(e)  The  fanction  of  the  liver . 

To  discover  the  absorbing  apparatus  and  how  it  is  used. 


Laboratory  Suggestions 

Demonstration  of  food  tube  of  man  (manikin).  —  Comparison  mthfood 
tube  of  frog.  Drawing  (comparative)  of  food  tube  and  digestive  glands 
of  frog  and  man. 

Demonstration  of  simple  gland.  —  (Microscopic  preparation.) 

Home  experiment  and  laboratory  demonstration.  — ■  The  digestion  of 
starch  by  saliva.     Conditions  favorable  and  unfavorable. 

Demonstration  experiment.  —  The  digestion  of  proteins  with  artificial 
gastric  juice.     Conditions  favorable  and  unfavorable. 

Demonstration.  —  An  emulsion  as  seen  under  the  compound  microscope. 

Demonstration.  —  Emulsification  of  fats  with  artificial  pancreatic 
fluid.     Digestion  of  starch  and  protein  with  artificial  pancreatic  fluid. 

Demonstration  of  "tripe"  to  show  increase  of  surface  of  digestive  tube. 

Laboratory  or  home  exercise.  —  Make  a  table  showing  the  changes  pro- 
duced upon  food  substances  by  each  digestive  fluid,  the  reaction  (acid  or 
alkaline)  of  the  fluid,  when  the  fluid  acts,  and  what  results  from  its  action. 

To  THE  Teacher.  —  The  chief  purpose  of  this  chapter  is  to  make  plain  the  chem- 
ical changes  that  take  place  during  the  process  of  digestion.  The  experiments  given 
have  been  found  to  be  much  more  useful  for  immature  minds  of  first-year  students 
than  a  longer  series  of  conditions,  which,  although  necessary  for  the  fulfillment  of 
the  technically  correct  experiment,  are  nevertheless  extremely  confusing  to  the 
beginner.  We  here  deliberately  sacrifice  some  of  the  factors  in  the  experiment  in 
order  to  maintain  interest  and  obtain  understanding. 

The  absorption  of  foods  is  a  difficult  subject  even  for  the  adult,  so  experimental 
work  is  not  deeply  treated.  Nor  should  much  more  than  memory  work  be  ex- 
pected at  this  time  because  of  the  several  factors  involved  and  the  extreme  diffi- 
culty of  their  control.     We  cannot  expect  our  teachers,  much   less  our  pupils,  to 

220 


PROBLEM    184  221 

be  expert  physiological  olioniisls.  Hut  we  ean  obtain  and  undorstand  some  of  the 
data  involved.  It  is  with  such  an  end  in  view  that  tho  rather  curtailed  li.st«  of 
important  happenings  in  the  process  are  here  outlined. 

Problem  184'  To  compare  the  digestive  systmyv  of  a  fro^  with 
that  of  man. 

Materials.  —  Opened  frogs  preserved  in  4  per  cent  foi  inalin, 
manikin  showing  digestive  tract,  opened  frogs'  stomachs,  hand 
microscopes,  charts  of  digestive  systems  or  cHagrams  on  jiage  297, 
Civic  Biology. 

Method  and  Observations.  —  Note  in  the  opened  specimen 
of  the  frog  the  ghstening  membrane  {peritoneum)  hning  the  body 
cavity.  It  is  this  membrane  in  man  that  becomes  inflamed  and 
causes  peritonitis. 

Notice  the  large,  reddish  brown  organ  covering  most  of  the  other 
organs.  This  is  the  liver.  Count  the  lobes  or  divisions  of  the  hver 
and  compare  the  position  and  general  structure  with  the  liver 
of  man  (use  manikin).  Lift  up  the  middle  lobe  of  the  liver  and 
find  the  gall  bladder,  a  greenish  sac.  This  contains  bile,  a  secre- 
tion from  the  liver.  Now  compare  with  the  manikin  to  see  if  you 
can  locate  where  the  bile  gets  into  the  food  tube. 

The  food  tube  begins  at  the  mouth,  continues  as  a  short  wide 
gullet  into  the  stomach  (just  under  the  liver).  Compare  these 
structures  in  the  frog  with  similar  structures  in  man.  The  stom- 
ach of  the  frog  leads  into  a  long  coiled  stiudl  intestine  and  thence 
into  a  very  short  large  intestine.  What  difference  is  there  between 
the  frog  and  man  in  this  respect  ?  Note  that  all  the  organs  are  held 
in  place  by  a  fold  of  the  body  cavity  lining  called  the  mesentery. 
What  might  its  use  be?  A  pinkish  body,  the  i)<in.crcas,  can  be 
located  between  the  stomach  and  the  first  bend  of  the  small 
intestine. 

Look  at  the  open  stomach ;  notice  th(^  folds  and  lidgo'^  on  the 
inner  wall  and  determine  which  way  they  run. 

Look  at  a  mounted  section  of  the  small  intestine  of  a  dog  or  a 
cat  through  a  comj^ound  microscope  (<»  note  the  small  elevations 
of  its  inner  lining  called  /////".  \\'()uld  these  projections  give  more 
surface   to    the   small    intestine? 

Conclusion.  —  1.  Compare,   part    for  part,   the  digestive   tract 


222 


DIGESTION   AND   ABSORPTION 


of  a  frog  with  that  of  a  man.     In  what  respects  are  they  similar  ? 

Different  ? 

2.  Of  what  uses  might  the  ridges  in  the  stomach  be?     The 

folds  and  villi  in  the  intestine?     (Remember  the  purpose  of  the 

food  tube  is  to  prepare  food  to  become  part  of  the  blood.) 

Drawing.  —  Draw  the  food  tube  and  glands  of  the  frog  and 

show  all  parts.     On  the  same  page,  using  the  manikin,  draw  the 

food  tube  and  glands 
of  man.  Label  all 
parts  of  drawings. 

Problem    185:    To 

study  my  own  teeth. 

Materials.  —  A  mir- 
ror, teeth.  Figure, 
page  301,  Civic  Biology. 

Method.  —  Using  a 
small  mirror,  count 
your  teeth,  giving  the 
number  under  each  of 
the  following  heads : 

(a)  Incisors,  broad 
cutting  teeth  in  front. 

(b)  Canines,  pointed 
sharp  teeth  next  to 
the  incisors. 

(c)  Premolars,  grind- 
ers with  two  points  on 
the  biting  surface. 

(d)  Molars,  teeth 
with  more  than  two 
points,  in  the  back  of 
the  mouth. 

Observations.  — 
What  are  the  numbers 
and  uses  of  each  of  the 
above  kinds  of  teeth  ? 


PROBLEM    18(;  223 

Examine  carefully  in  a  stronjr  li^rlit  oach  of  your  (eedi  and 
answer  the  following  questions,  marking  the  points  asked  for 
on  a  chart  of  your  teeth  copied  from  the  preceding  diagram. 
1.  With  a  bracket,  label  each  group  of  teeth.  2.  With  a  cross, 
mark  all  the  teeth  you  have  lost  or  that  iiave  not  gnjwn.  3.  Mark 
all  cavities  not  filled  in  your  teeth  by  a  si)ot  when-  the  cavity 
exists.  4.  If  teeth  have  been  filled,  crowned,  etc.,  mark  witli 
appropriate  title. 

Conclusion.  —  What  is  the  condition  of  my  teeth?  ShouM  I 
go  to  a  dentist? 

Prohlein  186:  To  demonstrate  the  function  and  structure  of 
a  simple  gland. 

Materials.  —  FehUng's  solution,  test  tube,  cracker,  stained 
shde  showing  longitudinal  and  cross  sections  of  a  gland. 

a.  Function 

Method  and  Observations.  —  Think  of  a  lemon  or  a  pickle. 
What  happens  in  your  mouth?  Collect  some  of  the  saliva. 
What  is  its  appearance? 

Chew  up  a  cracker  having  no  sugar  in  it.  After  the  mass  is 
well  mixed  with  saliva  put  in  the  test  tube  and  place  the  tube  in 
warm  water  for  an  hour.  Then  test  with  Fehhng's  solution. 
What  is  the  result  ? 

Conclusion.  —  1.  With  what  structures  in  the  human  body  is  a 
gland  connected? 

2.  What  is  one  function  of  the  juice  poured  out  by  the  salivary 
glands  of  the  mouth? 

b.  Structure 

Observations.  —  Under  the  microscope,  notice  the  structure  of 
a  gland  in  both  cross  and  longitudinal  sections.  Witli  wiiat  is  the 
wall  lined?  What  is  the  shape  of  the  gland?  (See  textbook.) 
If  work  is  done  by  a  gland,  then  it  nuist  have  food  to  do  this  work. 
Might  the  material  poured  out  of  a  gland  l)e  manufactured  from 
the  food  it  gets  ? 

What  structures  would  of  necessity  go  to  a  gland  to  take  food 
there?     Look  at  the  diagram  in  your  textbook. 


224  DIGESTION   AND   ABSORPTION 

Conclusion.  —  1.  Write  a  paragraph  telling  the  uses  and  struc- 
ture of  a  gland. 

2.  Make  a  diagram  showing  the  parts  of  a  gland. 

Proble^n  187 :  To  find  the  use  of  digestion. 

Materials.  —  Starch  paste,  saliva,  thistle  tubes  with  membrane 
covers,  Fehling's  solution,  lamp,  battery  jar  containing  warm 
water  (about  100°  F.). 

Method.  —  In  one  thistle  tube  place  some  saliva  mixed  with 
starch  paste.  In  a  second  tube  place  some  paste  and  water. 
Fasten  membrane  covers  over  the  thistle  tubes,  and  wash  carefully 
to  rid  of  all  starch  or  other  material  on  outside  of  tube.  Then 
place  the  two  thistle  tubes,  large  end  down,  in  the  jar  containing 
warm  water.  Next  test  some  saliva  with  Fehling's  solution. 
Is  there  any  grape  sugar  present?  At  the  end  of  the  laboratory 
period  test  the  contents  of  the  jar  with  iodine  and  with  Fehling's 
solution.     Was  there  any  starch  in  the  water?     Grape  sugar? 

Conclusion.  —  1.  What  caused  the  presence  of  this  grape  sugar 
in  the  jar? 

2.  How  did  it  get  into  the  jar? 

Prohle^n  188 :  To  determine  the  conditions  most  favorable 
for  gastric  digestion. 

Materials.  —  Test  tubes,  eggs,  hydrochloric  acid,  pepsin,  caustic 
soda,  copper  sulphate. 

Method.  —  Use  five  test  tubes  or  beakers  and  some  boiled  white 
of  egg.  In  No.  1,  place  minced  white  of  egg  and  water ;  in  No.  2, 
place  minced  white  of  egg  and  .2  per  cent  hydrochloric  acid ; 
in  Nos.  3,  4,  and  5,  place  minced  white  of  egg,  .2  per  cent  hydro- 
chloric acid  and  pepsin. 

Keep  the  first  three  in  a  warm  place  at  about  a  temperature  of 
blood  heat  for  several  hours.  Keep  No.  4  in  an  ice  box  or  sur- 
rounded by  cracked  ice.  Keep  No.  5  in  boiling  water  for  15  or 
20  minutes,  then  place  it  in  the  warm  place  with  Nos.  1,  2,  and  3. 

Observations.  —  Test  No.  1  with  biuret  test  ^  for  the  presence  of 

1  Biuret  solution :  To  the  material  to  be  tested  add  its  own  bulk  of  concen- 
trated caustic  soda.  Then  add  a  drop  or  two  of  weak  copper  sulphate  solution. 
A  violet  or  blue  color  shows  the  presence  of  unchanged  protein,  a  rose  pink  the 
presence  of  peptone. 


PROBLKIM    101  225 

a  soluble  protein  (a  peptone).  Test  Nos.  2,  3,  4,  and  5  with  biuret 
test,  noting  results,  and  remembering  that  whenever  there  is 
peptone  present  the  mixture  in  the  test  tube  shows  a  rose  pink  color. 
Conclusion.  —  1.  What  conditions  are  necessary  iur  the  diges- 
tion of  protein? 

2.  What  is  the  effect  of  an  extreme  heat  and  cold  on  the  action 
of  hydrochloric  acid  and  pepsin  with  a  protein? 

3.  Make  a  table  to  give  all  your  results  of  the  above  tests  of 
conditions  necessary  for  digestion  of  protein. 

Problem  ISO:  To  determine  another  effect  of  gastric  juwe. 
Materials.  —  Lime  and  hydrochloric  acid. 
Method.  —  To  a  little  lime  add  weak  hydrochloric  acid. 
Observations.  —  What  happens? 

Conclusion.  —  What  might  be  the  effect  of  gastric  juice  upon 
certain  salts  taken  into  the  body  ? 

Problem  190:  To  note  the  action  of  pancreatic  Juice  on 
starch. 

Materials.  —  Make  some  artificial  pancreatic  juice  by  mixing  ') 
grains  of  pancreatin  and  10  grains  of  baking  soda  in  100  c.c.  of 
water,  Fehling's  solution. 

Method.  —  Add  some  of  this  artificial  pancreatic  juice  to  some 
dilute  starch  paste.  Keep  at  about  body  temperature  for  a  few 
hours,  then  test  with  Fehling's  solution. 

Observations.  —  What  occurred  when  Fehling's  solution  was 
added  ? 

Conclusion.  —  What  was  the  action  of  pancreatic  juice  on  starch  ? 

Problem  191:  To  note  the  effect  of  pancreatic  Juice  on  oils 
and  fats. 

Materials.  —  Test  tube,  oils,  baking  soda. 

Method.  —  Shake  up  oil  and  water.  What  hapi)ens?  Then 
add  a  little  alkaline  substance,  c.f/.,  baking  soda.  What  hap- 
pens? Now  shake  up  water  with  artificial  pancreatic  juice. 
What  happens? 

Note.  —  An  emulsion  is  formed  hy  brcakiuK  fats  up  into  very  small  droplets 
which  float  in  a  liquid,  making  a  milky  appearance.     In  addition  to  emulsifying 
HUNTER    LAB.    PUOB.  —  15 


226 


DIGESTION  AND  ABSORPTION 


fats,  pMiioreatic  juice  changes  them  into  soft  soaps  and  fatty  acids.     Fat  in  this 
form  may  be  absorbed.      (See  page  306,  Civic  Biology.) 

Conclusion.  —  1.  What  conditions  are  necessary  to  make  an 
emulsion  ? 

2.  What  is  the  effect  of  pancreatic  fluid  on  oils? 

Problem  192:  To  study  the  effect  of  artificial  pancreatic 
juice  on  protein. 

Materials.  —  Artificial  pancreatic  juice,  caustic  soda,  copper 
sulphate. 

Method.  —  Using  artificial  pancreatic  juice  instead  of  a  mixture 
of  hydrochloric  acid  and  pepsin,  carry  out  an  experiment  as  de- 
scribed for  tube  No.  3  of  Problem  188. 

Observations.  —  Was  any  of  the  white  of  egg  digested? 

Conclusion.  —  Make  a  table  to  show  the  effect  of  pancreatic 
juice  on  nutrients. 

Brohlem  193 :  To  find  one  action  ofhile. 

Materials.  —  Ox  gall  or  bile,  olive  oil,  parchment  paper,  funnels. 

Method.  —  Take  two  funnels,  place  parchment  paper  in  each. 
Moisten  one  paper  with  bile,  the  other  with  water.  Then  place 
an  equal  amount  of  olive  oil  in  each  funnel. 

Observations.  —  Through  which  funnel  does  the  oil  pass  more 
freely  ? 

Conclusion.  —  What  effect  might  bile  have  on  the  wall  of  the 
intestine  ? 


Summary  of  the  Uses  of  Human  Food  Tube  and  Glands 

Digestive  System  of  Man 

r  Teeth 
Mouth  <  Tongue 

I  Glands  —  saliva  —  digests  starch 
Pharynx. 
Esophagus 
Stomach— glands— gastric  juice— digests  proteins — dissolves  lime  salts 

Liver — bile  —  helps  fat  absorption 

r  starch 

Pancreas — pancreatic  juice — digests  |  protein 

I  oils 
.  Absorption  of  digested  foods 

Large  intestine  —  slight  absorption  of  soluble  foods  and  wastes 


Alimentary 

Canal 

and 

Digestive 

Glands 


Small  intestine — glands  ■ 


PROBLEM   106 
Fill  out  a  diagram  like  tlie  folhjwing : 


2'n 


Glands 

Locatiim 

Juice 

Ferment* 

Action 

Tieffull 

A-f  f  i  o  r\ 

HowJ»|t 

Action 

Probletn  194::  To  study  the  method  and  place  of  absorption 
in  the  human  body. 

NOTE.  —  Absorption  is  the  process  by  which  digested  food  passes  from  the 
digestive  canal  through  the  walls  of  the  blood  vessels  into  the  blood. 

Materials.  —  Tripe,  slides  showing  villi,  charts. 

Observations.  —  Study  the  structure  of  trijx^  (stomach  wall) 
and  the  microscopic  slide  of  a  cross  section  of  the  small  intestine. 
Remember  that  the  chief  function  of  the  small  intestine  is  to  get 
food  into  the  blood. 

Make  a  tube  of  paper  having  a  diameter  of  1  inch.  Then  try 
to  make  a  tube  having  the  same  diameter  Ijut  lia\  ing  a  folded  wall. 
Which  takes  more  paper?     Which  would  present  more  surface? 

Conclusion.  —  How  is  the  structure  of  the  wall  of  the  intestine 
fitted  for  absorption? 

Problem  Wr>:  To  understand  the  structure  of  a  villus. 

Method.  —  Study  the  figure  of  the  villi  on  page  307,  Civic  Biol- 
ogy; make  sure  you  understand  tlie  use  of  each  part. 

Conclusion.  —  1.  If  blood  goes  into  \\\o  villus,  what  change 
in  its  composition  might  take  place  witliin  it? 

2.    How  do  fats  get  into  the  villi?     What  becomes  of  the  fats? 

Problem  lf)(i :  IIoiv  uuty  foods  be  absorbed  by  the  rilli? 

Observations.  —  Suppose*  the  villus  is  lined  with  a  dclicMlc  -kin- 
like covering.  How  might  li(|ui(l  food  pass  through?  Suppose 
movements  of  other  organs  should   i)ress   upon   or  s(j:ieezc   the 


228 


DIGESTION   AND   ABSORPTION 


intestines.     Would  any  food  be  forced  through?     Might-  fluids 
pass  through  in  the  same  way  as  a  sponge  absorbs  water? 
Conclusion.  —  In  what  ways  is  liquid  food  absorbed? 

Problem  19  7 :  To  find  the  pathway  of  absorbed  foods. 

Method.  —  Study  the  diagram  on  page  309,  Civic  Biology;  re- 
member that  digested  food  is  within  the  intestine.  Follow  the 
course  of  sugars  and  digested  proteins  as  far  as  the  heart.  What 
happens  to  the  blood  vessels  in  the  liver? 

NOTE.  — Sugar  is  taken  from  the  blood  and  stored  as  animal  starch  {glycogen) 
in  the  liver  and  muscles.  Fat  during  the  process  of  digestion  by  the  pancreatic 
juice  is  split  into  fatty  acids  and  glycerin  and  is  absorbed  as  such.  In  the  villi, 
these  fatty  acids  and  glycerin  are  rebuilt  into  small  fat  particles.  They  pass 
through  the  lymph  capillaries,  called  the  lacteals,  which  empty  into  the  thoracic 
duct  and  thence  into  the  heart  and  circulation. 

Conclusion.  —  1.  Write  a  brief  paragraph  summarizing  the 
different  pathways  by  which  food  reaches  the  heart  and  general  cir- 
culation. 

2.  Complete  the  following  table  : 


Food  s 

VT'Kere 
A"b  sorted 

Torrrv 

Adoptations 

PcrtKs 
to  Heart 

' 

1 

Problem  Questions 

1.  What  are  the  uses  of  (a)  the  incisors,  {h)  the  canines,  (c)  the 
premolars,  and  {d)  the  molars? 

2.  How  many  teeth  are  there  in  our  first  set  of  teeth?     When 
do  they  begin  to  come,  and  when  do  they  go? 

3.  What  makes  teeth  decay? 

4.  Why  should  we  clean  the  teeth  night  and  morning? 


REFERENCE   BOOKS  22!) 

5.  What  harm  ini«;ht  oomo  from  s\vall()\viM<r  fluids  which  pass 
through  a  mouth  containing  decayed  teeth? 

6.  How  often  should  one  visit  th(»  (h^ntist?     Why? 

7.  How  does  the  practice  of  Fletclierism  help  digestion? 

8.  What  is  a, gland?     What  work  does  it  do? 

9.  What  are  the  digestive  glands  of  the  human  hody? 

10.  Tell  where  each  part  of  a  meal  of  bread  and  butter,  meat, 
rice  pudding,  and  nuts  is  digested. 

11.  Why  should  we  chew  starchy  foods  well  before  swallowing? 

12.  Why  is  soup  eaten  at  the  beginning  of  a  meal  ?     (Remember 
it  is  absorbed  rapidly.) 

13.  Why  are  partly  cooked  foods  harder  to  digest  than  well- 
cooked  foods? 

14.  Name  three  easily  digested  foods  and  tell  why  they  are  easy 
to  digest. 

15.  Name  three  foods  difficult  to  digest  and  tell  the  reasons  why. 

16.  Give,  in  detail,  the  digestion  of  a  meal  of  milk,  apple  sauce, 
and  bread. 

17.  Where  is  food  absorbed? 

18.  How  is  food  absorbed? 

19.  Why  is  it  necessary  that  food  be  absorl)ed? 

20.  Where  and  how  do  fats  get  into  the  blood? 

21.  What  happens  to  fats  before  they  get  out  of  the  intestine? 
Before  they  get  out  of  the  villus? 

22.  Why  do  salt  and  water  need  no  digestion? 

23.  What  changes  take  place  in  the  composition  of  blood  in  the 
walls  of  the  small  intestine?  In  the  walls  of  the  stomach?  In 
a  gland  ?     In  the  liver  ? 

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Hunter,  Essentials  of  Biology,  Chap.  XXV.     American  Book  Conn)any. 
Abderhalden,   Defensive   Ferments   of   Animal  Organisms.     (Advanced.)     William 

Wood  and  Company. 
Atwater,  Principles  of  Nutrition,  and  Nutritive  Value  of  Food.      I'^armcrs'  Bulli'tin 

142,  U.  S.  Department  of  AKriculture.  1900. 
Bailey,  Source,   Chemistry,  and    Use  of  Food  Products.     V.    Blakiston'a  Son  and 

Company. 
Brady,  Eating  for  Efficiency.     Technical  World,  May,  1914. 


230  DIGESTION   AND   ABSORPTION 

Bread.     Farmers'  Rulletin  389,  Experiment  Station  Bulletins  67,  126,  and  143. 

Hryant,  School  Feeding.     (Advanced.)     J.  B.  Lippincott  Company. 

Bryce,  Modern  Theories  of  Diet.     Longmans,  Green  and  Company. 

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Conley,  Nutrition  and  Diet.     American  Book  Company. 

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Day,  Digestibility  of  Starch  as  Affected  by  Cooking.  Bulletin  202,  Experiment 
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116,  129,  149,  150,  152,  221,  223. 

Drugs.  Chemistry  Bulletins  80,  98,  126.  Farmers'  Bulletins  377,  393.  Depart- 
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Eddy,  Textbook  in  General  Physiology  and  Anatomy.     American  Book  Company. 

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121,  122,  124,  128,  142,  149,  152,  162,  169,  193,  203,  227,  234,  244,  249,  273, 
276,  293,  295,  298,  316,  332,  342,  348,  359,  363,  375,  388,  391,  708. 

Fink,  Food  and  Flavor.     The  Century  Company. 

Fischer,  Physiology  of  Alimentation.     John  Wiley  and  Sons. 

Food  Charts  of  Department  of  Agriculture. 

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Forster  and  Weigley,  Food  and  Sanitation.     Row,  Peterson  and  Company. 

Frankland,  Bacteria  in  Daily  Life.     Longmans,  Green  and  Company. 

Gouraud,  What  Shall  I  Eat  f     Rebman  Company. 

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Human  Nutrition,  Farts  I  and  II.  Cornell  University  Reading  Course,  Ithaca, 
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Kahn,  Wise  Eating  and  Good  Health.     Craftsman,  June  13,  1914. 

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Kerley,  The  Nutrition  of  School  Children.     The  Macmillan  Company. 

Locke,  Food  Values.     D.  Appleton  and  Company. 

Lorand,  Health  and  Longevity.     F.  A.  Davis  Company. 

Lusk,  Fundamental  Basis  of  Nutrition.     Yale  University  Press. 

Meat.  Farmers'  Bulletins  34,  162,  183,  193,  391  ;  Experiment  Station  Bulletins 
102,  141,  193;  Chemistry  Bulletins  13,  114.  Department  of  Agriculture, 
Washington,  D.  C. 

Metabolism.     Experiment  Station  Bulletins  45,  69,  109,  136,  175,  208. 

Milk.  Farmers'  Bulletins  42,  69,  149,  227,  237,  273  ;  Animal  Industry  Bulletins 
1,  73,  104,  117,  151,  153;  Hygienic  Laboratory  Bulletin  56.  Department  of 
Agriculture,  Washington,  D.C. 

Murray,  The  Economy  of  Food.     D.  Appleton  and  Company. 

Norton,  Food  and  Dietetics.     American  School  of  Home  Economics,  Chicago,  111. 

Nostrums  and  Quackery.     American  Medical  Association. 

Nutrition.  Experiment  Station  Bulletins  35,  52,  53,  84,  91,  107,  159,  187.  Depart- 
ment of  Agriculture,  Washington,  D.C. 


REFERENCE   B(J()KS  231 

Preservatives.  Chemistry  Circulars,  15,  2S,  37,  39,  42;  Chemistry  Bulletin  84; 
Agriculture  Year  Book,  1900,  1903.  190').  190S. 

Respiration  Calorimeter.     Experiment  Station  Bulletins  44,  (V.i  \    Year  B(jf>k.  1901. 

Rexford.  One  Portion  Food  Table.      Published  by  author. 

Rosenau,  All  about  Milk.     Metropolitan  Life  Insurance  Company. 

Rosenau,  The  Milk  Question.     Houghton  Mifflin  Company. 

Russell,  Strength  and  Diet.     Longmans,  Green  and  Company. 

Sherman,  Food  Products.     The  Macmillan  Company. 

Spargo,  The  Common  Sense  of  the  Milk  Qucstiort.     The  Macmillan  Company. 

Stiles,  Nutritional  Physiology.     W.  B.  Saunders. 

Taylor,  Digestion  and  Metabolism.     Lea  and  Febiger. 

The  Waste  of  Overeating.     Success  Magazine,  March,  1910. 

Thompson,  Practical  Dietetics.     D.  Appleton  and  C^ompany. 

Vegetables.  Experiment  Station  I^.ulletins  43,  GS ;  Farmers'  Bulletin  250.  De- 
partment of  Agriculture,  Washington,  D.C. 

Wade,  X-ray  Pictures  of  Digestive  Tract.     Scientific  American,  May  9,  1914. 

Wardall  and  White,  A  Study  of  Foods.     Giun  and  Company. 


XXI.     THE  BLOOD   AND   ITS   CIRCULATION 

Problems.  —  To  discover  the  co7)%}:>osition  and  uses  of  the  dif- 
ferent parts  of  the  blood. 

To  find  out  the  vveans  by  which  the  blood  is  circulated  about 

the  body. 

Laboratory  Suggestions 

Demonstration.  —  Structure  of  blood,  fresh  frog's  blood  and  human 
blood.     Drawings. 

Demonstration.  —  Clotting  of  blood. 

Demonstration.  —  Use  of  models  to  demonstrate  that  the  heart  is  a 
force  pump. 

Demonstration.  —  Capillary  circulation  in  web  of  frog's  foot  or  tad- 
pole's tail.     Drawing. 

Home  or  laboratory  exercise.  —  On  relation  of  exercise  on  rate  of  heart- 
beat. 

To  THE  Teacher.  —  To  prove  that  blood  contains  liquid  food  and  to  show  how 
blood  is  made  are  the  first  considerations  in  this  chapter.  The  uses  of  the  cor- 
puscles may  well  be  shown  in  part  by  experiment.  Proof  of  circulation  of  the  blood 
centers  around  two  experiments  :  e\ddence  that  the  heart  is  a  force  pump  and  the 
demonstration  of  capillary  circulation  in  the  tadpole's  tail.  Interesting  and  vital 
laboratory  work  may  be  done  by  comparing  graphs  of  the  heartbeat  of  members 
of  the  class  when  at  rest,  after  mental  work,  and  after  physical  work.  Interesting 
correlations  between  physiologic  age,  sex,  and  rate  of  heartbeat  may  also  be 
worked  out.  The  importance  of  ferments  in  the  blood  is  a  new  and  fascinating 
topic  to  which  time  should  be  devoted  if  materials  are  available  to  the  teacher. 

Problem  198 :  To  prove  that  blood  contains  nutrients. 

Materials.  —  Ox  blood,  nitric  acid,  ammonia,  Fehling's  solution, 
formalin,  iodine,  test  tubes,  lamp,  egg  beater. 

Method.  —  Collect  some  blood  at  a  slaughter  house.  Set 
aside  one  bottle  to  clot  (label  it  clotted  blood).  Place  some  of 
the  fresh  blood  in  a  flat  bowl  and  beat  it  with  an  egg  beater.  Fill 
a  bottle  with  the  red  liquid  (label  it  defibrinated  blood).  After 
washing,  place  the  fibrin,  or  threads  which  stick  to  the  egg  beater, 
in   a   third   bottle.     Pour  4  per   cent  formalin  on  the  fibrin  to 

232 


PROBLl'.M    1<J9  2:53 

preserve  it.  We  have  said  that  blood  is  made,  in  part  at  least,  of 
digested  foods.  In  the  bottle  containing  the  clotted  blood  notice 
the  solid  part,  the  clot,  and  a  yellowish  licjuid  called  .scnufi. 

Pour  off  some  of  the  sermii  into  each  of  three  test  tubes. 

Test  the  first  with  iodine  solution.  —  Result  ? 

Test  the  second  with  Fehling's  solution.  —  Result '.' 

Test  the  third  with  nitric  acid  and  ammonia.  What  is  the 
result  ? 

Test  some  of  the  blood  fibrin  with  nitric  acid  and  ammonia. 

Observations.  —  Note  what  happens  in  each  of  the  three  tubes. 
What  is  fibrin  ? 

Conclusion.  —  1.    What  nutrients  are  present  in  blood  .serum? 

2.  Of  what  is  fibrin  composed  ? 

3.  What  nutrients  are  present  in  blood? 

Note.  —  The  blood  clot  is  composed  in  part  of  structures  (larcely  protein) 
known  as  corpuscles.  These  can  better  be  seen  in  prepared  specimens  under  the 
compound  microscope. 

Problem  199 :  To  study  the  corjniscles  of  the  blood. 

a.    In  Frog 

NOTE.  —  Blood  is  composed  of  two  principal  parts,  solid  bodies  (corpuscles) 
and  a  liquid  (plasma). 

Materials.  —  Frogs,  glass  slide,  cover  glasses,  microscope. 

Method.  —  Place  some  frog's  blood  on  a  glass  slide,  cover  and 
examine  under  a  compound  microscope. 
(See  figure.) 

Observations.  —  What  are  the  color 
and  shape  of  the  corpuscles  that  are  most 
numerous  and  most  easily  seen?  These 
are  red  corpuscles. 

There  are  other  irregular-shaped  cor- 
puscles,   more    transparent   and    not   so         ^ 
easily  seen.     These  are  the  colorless  cor-        coupuscle  of  Fu..u. 
puscles. 

Conclusion.  —  1.  What  kinds  of  (•ori)iiscles  did  you  find".' 

2.  Are   corpuscles  cells?     Can  you  provi*  your  statement? 


2U 


THE  BLOOD  AND  ITS  CIRCULATION 


Corpuscle  of  Man. 


b.    In  Man 

Observations.  —  Using  a  slide  of  your  own  blood,  note  that  red 
corpuscles  have  no  nucleus.     (They  do  when  they  are  young.) 

Are  they  cells?  Do  you  .find  colorless 
(white)  corpuscles  as  well?  How  do  they 
compare  with  the  red  in  number? 

Conclusion.  —  How  does  the  structure  of 
blood  corpuscles  in  man  compare  with  those 
of  the  frog  ? 
The  following  -experiment  will  show  one  of  the  functions  of 
corpuscles. 

Prohlem  200 :  To  determine  the  effect  of  oxygen  and  carbon 
dioxide  upon  the  Mood. 

Materials.  —  Test  tubes,  defibrinated  blood,  calcium  carbonate, 
hydrochloric  acid,  oxone. 

Method.  —  Using  two  tubes  of  defibrinated  blood,  lead  a  tube 
from  a  bottle  containing  calcium  carbonate  and  hydrochloric  acid 
into  one  tube.     This  will  produce  carbon  dioxide  gas.     Lead  a 


^ 


C 


B1.0 


OD 


<r 


V. 


Oxygeiv 
penerator* 


Apparatus  for  Generation  of  Crbon  Dio.viue  and  Oxygen, 

A,  acid;  M,  marble. 


PROBLKM  201  2:i5 

tiiho  from  a  stoppered  botUe  coiitainiii<r  a  lilllc  piece  of  oxoiie 
(which  j>;ives  off  oxygen)  into  the  second  tiihe. 

Observations.  —  Note  the  chanj^e  of  coloi-  in  hotli  lest  tubes. 
The  change  from  a  deep  purple  to  a  scarlet  occurs  in  the  lun^ 
as  blood  passes  through  them. 

Conclusion.  —  1.  How  can  we  know  of  the  presence  of  oxygen 
in  the  blood?     Of  carbon  dioxide? 

2.  How  and  when  would  carbon  dioxide  get  into  the  blood? 
(Remember  the  cells  of  the  body  do  work.) 

Note.  —  The  red  corpuscles  contain  a  substance  known  as  hcemogluhin  which 
readily  unites  with  oxygen.  When  the  corpuscles  take  up  oxygen,  their  color 
changes  to  a  brighter  red. 

3.  How  is  the  oxygen  carried  in  the  blood  ? 

Problem  201 :  To  study  the  structure  of  the  heart. 

Materials.  —  Model  of  a  human  heart,  beef  heart  (opened), 
and  charts. 

Method.  —  Refer  to  chart  of  circulation,  page  321,  Civic  Biology. 
Find  the  heart,  arteries,  and  veins  connected  with  it.  Find  out 
where  the  chief  arteries  lead  and  from  where  tlie  large  veins 
come.  Also  examine  a  beef  heart  or  a  good  model  and  note  the 
four  chambers,  the  valves,  and  the  blood  tubes  leading  to  and 
from  it. 

Note.  —  The  upper  chambers  (see  model)  are  called  the  rij^ht  and  left  auridis 
respectively ;    the  lower  chambers  the  right  and  left  ventricles. 

Observations.  —  Which  have  the  thicker  walls  '^  What  is  prob- 
ably the  use  of  these  walls  ?  Notice  the  position  of  the  valves  and 
the  direction  of  their  movement.  In  what  direction  do  arteries 
lead?  Veins?  Into  how  many  chambers  is  the  heart  divided? 
Do  these  chambers  all  connect  with  one  another?  Can  you  find 
a  solid  wall  between  the  right  and  left  sides?  Can  you  show  the 
heart  to  be  a  double  force  pump?  Where  does  the  right  side  of 
the  heart  send  the  blood?     The  left? 

Conclusion.  —  Write  a  paragraph  describing  th(^  structure  of 
the  heart. 

Drawing.  — Make  a  drawing  from  the  model.     Liil)el  all  parts. 


236 


THE   BLOOD   AND   ITS   CIRCULATION 


Prohlem  "202 :  To  .^tudy  the  circulation  of  the  hlood. 

Materials.  —  Liviiiig  tadpole  under  influence  of  a  1  per  cent 
solution  of  chlorotone,  mounted  on  a  piece  of  board  having  a 
\  inch  hole  bored  in  one  end.  Place  the  thin  part  of  the  tadpole's 
tail  over  the  opening ;  keep  the  tadpole  moist  by  wrapping  it  in 
wet  cotton.  (The  fin  of  a  living  goldfish  or  the  web  of  a  frog's 
foot  may  be  used.) 

Observations.  —  Observe  the  network  of  small  blood  vessels 
containing  moving  disks,  the  corpuscles.  In  some  of  the  tubes  the 
blood  appears  to  move  in  spurts.  These  tubes  are  arteries  and 
lead  from  the  heart.  Trace  the  tiny  arteries  in  the  direction  the 
blood  flows  and  notice  they  divide  into  very  small  tubes  called 
capillaries  which  connect  the  arteries  with  tubes  called  veins. 
The  latter  lead  back  to  the  heart.  How  does  a  capillary  differ 
from  a  small  artery  or  a  small  vein  ?  Does  the  blood  flow  in  an 
artery  differ  from  the  flow  in  a  vein?  Describe  the  disk-like 
bodies  (red  corpuscles)  in  the  blood.  How  do  they  compare  in 
size  with  the  diameter  of  the  capillary  tube?  Make  a  copy  of 
the  following  diagram  in  colors,  labeling  all  parts,  showing  blue 
for  veins,  purple  for  capillaries,  and  red  for  arteries. 


Changes  in  the  Blood  within  the  Capillakies. 


Conclusion.  —  1.  How  does  blood  get  from  arteries  into  the  veins  ? 

2.  What  change  might  take  place  on  the  way?     Why? 

3.  What  causes  the  pulsation  (pulse)  in  the  arteries? 


PKOHLKM    2().j 


2:i: 


Problem  20S :  To  deterniiiie  tlie  rate  of  your  oini  hrorthrat. 

Method. — Take  your  own  pulso  by  placiii*!;  the  fourth  finder 
of  your  right  hand  on  the  left  wrist,  just  at  the  hase  of  the  tluunl) 
about  one  inch  up  on  the  wrist ;  or  phice  the  finj?(T  on  the  side 
of  the  head  just  in  front  of  the  ear.  After  gettinj^  the  pulso,  wait 
for  a  signal,  then  count  the  nunib(>r  of  beats  for  one  minute. 
Give  your  age  and  rate  of  your  pulse  per  minute  to  a  pupil  chosen 
to  place  the  returns  from  the  class  on  the  ])oard  arrangecl  ''by 
age."     Classify  boys  and  girls  separately. 


Hctte. 

Age       60-65      66  70 


of       P  \xl  s  e. 

71-75         76-80  81-85 


6(>  90 


12,6 

13. 

13.6 

14 

etc. 

Conclusion.  —  1.  From  this  table  make  a  grapii  tliat  will  siiow 
the  normal  heartbeat  of  the  pupils  of  your  class. 

2.  Does  sex  have  anything  to  do  with  the  rate? 

3.  Does  age? 

Problem  204=:  What  is  the  effect  of  hard  mental  work  nn  the 
pulse  heat  ? 

Method.  —  Under  the  direction  of  the  teacher  do  some  hard 
problems  in  arithmetic  for  about  five  minutes.  Now  count  pulse 
as  before  and  tabulate. 

Conclusion.  —  Does  mental  work  affect  the  heartbeat? 

Problem  20r> :   What  effect  has  e.vereise  on  the  heartbeat  ? 

Method.  —  Under  the  threction  of  a  leader,  take  a  hard  setiiim- 
up  drill  for  three  minutes  with  the  windows  open.  Couut  the 
pulse  beats  as  before  and  tabulate.  Also  not(^  any  difTerence  in 
respiration. 


238 


THE  BLOOD   AND   ITS   CIRCULATION 


Conclusion.  —  1.  What  effect  does  exercise  have  on  the  rate 
of  the  heartbeat?     Can  you  explain  the  reason? 

2.  Can  you  explain  the  difference  in  the  rate  of  respiration? 

3.  Make  two  graphs  superimposed  on  the  original  graph  (Prob- 
lem 203),  using  different  colors  to  indicate  the  difference  between 
the  normal  and  the  other  results  found  in  the  subsequent  experi- 
ments. 

Summary  of  Circulatory  System 

Fill  in  the  following  outline. 


/ 


Summary  of  Blood 
water 


Blood 


/ 


/serum'    digested  food 
Plasmas^  gl^^-^   \  waste  products 


\^  ,      /red  corpuscles 

Corpuscles<^^j^.^^  corpuscles 


Matenalg 

Source. 

Destination. 

Constitwervt 
pcir-t    of 
Bloo<r 

« 

Fill  out  the  above  table  and  account  for  each  part  of  the  blood. 


JProhlem  206 :  How  to  stop  the  flow  of  blood  in  case  of  an 
accident. 

Method.  —  Decide  first  whether  the  blood  is  issuing  from  an 
artery  or  from  a  vein.  How  would  you  know?  Then  apply  a 
tourniquet  made  from  a  stick  or  ruler  and  a  handkerchief 
or  towel,  using  a  stone  or  knife  to  press  down  on  the  blood 
vessel.     Apply  between  the  heart  and  the  cut. 

Imagine  the  arm  to  be  severed  below  the  elbow  and  practice 
applying  a  tourniquet   on  the  brachial  artery;    on  the  femoral 


REFERENCE   BOOKS 


2:i0 


artery.  Does  the  pulse 
stop  when  the  tourniquet  is 
appHod?  Exphxin  reason. 
Conclusion. —  1.  How 
would  you  go  to  work  to 
make  a  tourniquet  ?  D(^- 
seribe  fully. 

2.  Where  must  a  tourni- 
quet be  placed  when  an 
artery  is  cut?  Where 
when  a  vein  is  severed? 

3.  What  is  the  use  of 
the  tourniquet? 


Problem  Questions 

1.  What  proof  have  we  that  the  blood  contains  nutrients? 

2.  Is  the  blood  a  tissue?     Give  reasons. 

3.  What    effect    has    oxygen    upon    the   blood?     Wliat  causes 
this? 

4.  Why  is  the  heart  a  force  pump? 

5.  Why  is  the  heart  said  to  be  double? 

6.  Why  does  the  blood  circulate? 

7.  What  are  the  chief  differences  between  veins,  arteries,  and 
capillaries  ? 

8.  What  factors  may  cause  differences  in  the  rate  of  heartbeat? 

9.  Explain  what  we  mean  by  the  second  wind. 

10.  Explain  why  a  man  becomes  minded  in  a  hard  rac(\ 

11.  What  factors  might  injure  the  heart?     Give  reasons. 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XXI.     American  Hook  Poinpany. 

Hunter,  Elements  of  Biology,  Chaps.  XXIX,  XX.\.      .Vint-rican  Hook  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XX\I.      .\inerican  Hook  Company. 

HouKh  and  Sedgwick,  Elements  of  Physiology.     (Jinn  and  Company. 

Starlings,  Hum,an  Physiology.     Lea  and  Febiger. 

Stewart,  Manual  of  Physiology.     William  Wood  and  Company. 


XXII.     RESPIRATION   AND   EXCRETION 


Problems.  —  A  study  of  respiration  to  find  out : 

(a)  What  changes  in  blood  and  air  tahe  place  within  the 
lungs. 

(Jj)  The  mechanics  of  respiration. 
A  study  of  ventilation  to  discover : 
ia)   The  reason  for  ventilation. 

(b)  The  best  method  of  ventilation. 
A  study  of  the  organs  of  excretion. 

Laboratory  Suggestions 
—  Comparison  of  lungs  of  frog  with  those  of  bird  or 


Demonstration 
mammal. 

Experiment.  — 

Experiment.  — 

Experiment.  — 

Demonstration 
lungs? 

Demonstration  experiment.  —  What  are  the  best  methods  of  ventilat- 
ing a  room  ? 

Demonstration 

Demonstration 


The  changes  of  blood  within  the  lungs. 

Changes  taking  place  in  air  in  the  lungs. 

The  use  of  the  ribs  in  respiration. 

experiment.  —  What  causes  the  filling  of  air  sacs  of  the 


—  Best  methods  of  dusting  and  cleaning. 

—  Beef  or  sheep's  kidney  to  show  areas. 


To  THE  Teacher.  —  Respiration,  especially,  gives  ample  opportunity  for  simple 
experiments  which  can  be  performed  by  the  pupil.  The  changes  of  blood  within 
the  lungs  are  easily  demonstrated  by  any  pupil.  The  mechanical  factors  in  respi- 
ration are  easily  shown. 

The  subjects  of  ventilation  and  proper  care  of  the  home  give  innumerable 
opportunities  for  practical  experiments  by  the  pupils.  Care  must  be  taken,  how- 
ever, that  the  pupils  do  not  gain  wrong  impressions  from  experiments  on  the  burn- 
ing of  the  candles  within  a  box.  Recent  investigations  make  it  seem  certain 
that  carbon  dioxide  as  a  factor  in  ventilation  is  less  to  be  reckoned  with  than  the 
humidity  and  heat  factors.  Experiments  with  wet  and  dry  bulb  thermometers 
should  be  tried  in  closed  rooms  to  show  the  increase  in  the  water  content  of  air  and 
its  effect  upon  the  human  organism.  Other  experiments  will  doubtless  commend 
themselves. 

Experiments  to  show  proper  methods  of  dusting  and  cleaning  should  be  tried 
at  home  and  reported  upon  by  groups  of  pupils.  In  this  way  more  ground  may  be 
covered  in  a  given  time  and  more  individuals  interested  in  the  work. 

240 


PR()BLI:M   208  211 

Problem  '^07:  To  cmn[)arc  the  sfnirtuirs  of  fhr  Utiles  of  ttic 
frog  and  of  niaii. 

Materials.  —  Freshly  killed  frogs,  l)l()\vj)ipes,  cliarts  or  models 
of  human  lungs. 

Method.  —  Open  a  frog's  mouth  and  find  the  slitlikc  ojx'ning 
(glottis)  just  back  of  the  tongue.  Insert  a  i)]()wpip('  or  a  glass 
tube  and  blow  down  the  short  windpijie  (traclun)  which  branches 
into  two  divisions  leading  to  the  lungs  {bronchial  tubes). 

Observations. — -What  happens  to  the  lungs?  I^xamine  a 
section  cut  through  a  frog's  lung.  Is  it  hollow?  Now  compare 
the  baglike  lungs  of  the  frog  with  the  more  complicated  lungs  of 
man  (see  chart).  Do  you  find  the  same  structures  leading  in 
the  lungs  of  man? 

NOTE.  —  The  windpipe  divides  as  in  the  frog,  one  tube  going  to  each  lung.  The 
tubes  now  divide  like  the  branches  of  a  tree  in  smaller  tubes  (the  bronchial  tubes) 
which  end  in  grapelike  masses  of  small  thin-walled  sacs  called  alveoli. 

Which  part  of  the  lungs  of  man  would  be  elastic?  Of  tlie 
frog  ?     Why  ? 

If  blood  vessels  were  found  in  the  walls  of  these  sacs,  what  gas 
might  be  brought  in  the  blood  to  this  point?  Wiiat  gas  might  be 
in  the  air?  How  might  the  exchange  of  these  gases  take  placx*? 
Where  might  it  take  place? 

Conclusion.  —  1.  How  do  the  frog's  lungs  differ  from  those  of 
a  man? 

2.  Explain  how  jthe  structure  of  the  lungs  gives  a  large  area  of 
moist  membrane  separating  the  blood  on  the  one  hand  from  the 
air  on  the  other. 

3.  What  is  in  the  blood  that  might  get  to  the  air? 

4.  What  is  in  the  air  that  might  get  into  the  blood? 

Problem  20S :  To  deternmiie  changes  that  take  place  in  air 
in  the  lungs. 

NOTE.  —  Changes  have  already  been  noted  that  take  place  in  blood  within  the 
lungs.     Our  next  problem  is  to  see  what  changes  take  place  in  air  within  the  lungs. 

Materials.  —  Thermometer,  glass  plate,  limewater,  glass  tubing, 
test  tube,  glass  jar,  diagram,  i)age  X\\,  Civic  Biology. 

Observations.  —  Breathe  on  the  bulb  of  a  thermometer  and  re- 

HUNTER   LAB.    PROn. 16 


242  RESPIRATION   AND   EXCRETION 

cord  any  changes.  Breathe  gently  on  any  glass  or  polished  metal 
surface.     Note  what  happens. 

Take  a  moderate  breath,  and  force  air  (tidal  air)  by  means  of  a 
glass  tube  through  limewater.  Notice  what  occurs.  Note  dia- 
gram. 

Force  the  last  part  of  a  deep  expiration  (reserve  air)  through 
limewater.     Note  result. 

Fill  a  glass  jar  with  expired  air  by  the  downward  displacement  of 
water.  Invert  the  jar,  keeping  it  covered.  Remove  the  cover, 
and  introduce  into  the  jar  a  lighted  pine  splinter.  Does  it  con- 
tinue to  burn?  What  does  this  indicate?  Why?  (Air  loses 
about  one  fourth  of  its  oxygen  while  in  the  lungs.) 

Conclusion.  —  1.  What  are  the  changes  that  take  place  in  blood 
in  the  lungs? 

2.  What  does  air  gain  in  the  lungs?     What  does  it  lose? 

3.  What  is  one  reason  for  deep  breathing? 

Problem  209 :  To  find  the  capacity  of  the  lungs.  (After  Davi- 
son.) 

Materials.  —  Gallon  bottle,  cork,  curved  glass  tubing,  and  a 
large  pan. 

Method.  —  Fill  the  bottle  with  water,  place  water  in  the  pan, 
and  invert  the  bottle  in  the  pan.  Remove  the  cork,  insert  the 
end  of  the  tubing  under  the  bottle,  fill  the  lungs  to  the  fullest 
capacity,  and  force  air  into  the  bottle. 

Observations.  —  How  much  water  flows  'from  the  bottle? 
What  has  taken  place  ?  Place  a  mark  on  the  bottle  so  as  to  show 
the  point  to  which  you  drove  out  the  water  by  means  of  air. 
Now  with  a  graduate  fill  the  bottle  with  water  to  the  point  dis- 
placed.    Measure  the  amount  of  water. 

Conclusion.  —  How  much  air  do  you  conclude  your  lungs  can 
hold  if  100  cubic  inches  remain  in  the  lungs  after  you  have  ex- 
pelled all  you  were  able?  Remember  a  gallon  contains  231 
cubic  inches. 

Problem  210 :  To  study  the  mechanics  of  respiration. 
Method    and    Observations.  —  Notice   the   movements  of   the 
body  when  inhaling  and  exhaling  in  an  ordinary  breath  and  an 


PROBLEM   212 


213 


extra  deep  breath.     Place  your  hand  on  your  chest  and  take  a  deep 
breath.     What  happens  to  the  ribs? 

Conclusion.  —  Does  taking  in  air  {inspimiiOn)  nHjuirc  greater 
effort  than  sending  it  out  (expiration)?     Explain. 

Problem  2 11:  To  study  the  part  the  ribs  jAaij  in  respira- 
tion.    (Modified  from  Eddy's  General  Physiologij.) 

Method.  —  Using  some  strips  of  heavy  cardl)()ard  and  four 
paper  fasteners,  construct  a  model  as  shown  in  the  k^ft-liand 
figure.  The  largest  strip  of 
cardboard  represents  the  back- 
bone. Parallel  to  it  is  the 
breastbone  or  sternum.  The 
cross  pieces  are  two  of  the 
ribs. 

Observations.  —  What  hap- 
pens to  the  distance  between 
the  backbone  and  the  sternum 
of  our  model  when  the  mus- 
cles raise  the  ribs  to  a  hori- 
zontal position  as  shown  in 
the  right-hand  figure  ? 

Conclusion.  —  What    hap- 
pens to  the   capacity   of   the    chest   cavity   when   the    ribs    are 
raised  ? 

Problem  212 :  What  is  the  function  of  the  diapJira^ni  ? 

Materials.  —  Small  bell  jar  with  opening  at  top  for  rubber  cork 
containing  one  opening,  Y  tube,  l)all()()ns,  and  rul)b('r  sheet 
arranged  as  shown  on  page  333,  Civic  Biology. 

Method.  —  The  glass  tube  represents  the  trachea  ;  tlie  branches, 
the  bronchial  tubes;  the  balloons,  th(»  huigs ;  tlie  lubbcr  sheet, 
the  diaphragm;  and  the  walls  of  the  ihest  cavity  arc  repre- 
sented by  the  sides  of  the  glass  bell  jar. 

Observations.  —  Lower  the  diaphrnirni  by  |)uniiig  the  rul)ber 
sheet  downward.  What  is  tlie  effect  on  tlie  air  capacity  of  the 
jar  when  the  rubber  is  pulled  down? 


244 


RESPIRATION   AND   EXCRETION 


Conclusion.  —  1.  What  makes  the  balloons  expand? 

2.  Write  a  statement  comparing  the  action  of  the  rubber  sheet 
with  that  of  your  own  diaphragm.  (Remember  that  the  action 
of  ribs  and  diaphragm  tends  to  make  the  chest  cavity  larger 
during  an  inspiration.) 

3.  Explain  fully  why  the  lungs  expand. 

4.  Explain  the  figure  on  page  331,  Civic  Biology,  and  make  a 
summary  of  all  the  changes  both  in  the  blood  and  in  the  lungs. 

Problem  '^13 :  To  find  out  what  becomes  of  the  oxygen  in  the 
lungs. 

Note. — We  know  that  the  oxidation  of  food  does  not  take  place  to  any  great 
extent  in  the  lungs,  but  in  the  cells  of  the  body  where  work  is  done.  (See  Civic 
Biology,  pages  331  and  332.) 

Observations.  —  Tell  what  the  figure  on  page  332,  Civic  Biol- 
ogy, illustrates,  and  observe  the  wastes  that  are  given  off  after 
food  in  the  cell  is  oxidized. 

Conclusion.  —  1.  What  carries  the  oxygen  to  the  cells  and 
where  does  it  get  to  these  carriers  ? 

2.  What  did  the  oxygen  do  after  it  got  near  the  cell  that  needed 
it? 

3.  What  are  the  wastes  formed  when  oxidation  takes  place? 

4.  What  is  the  purpose  of  oxidation  ? 

JProble^n  214 :  To  make  a  study  of  ventilation. 

Materials.  — A  grooved  box  8  X  10  inches  at  base,  8  inches  high, 
with  sliding  glass  door.     Place  on  side  and  have  4  half-inch  holes, 

two  at  top  and  two 
at  bottom,  bored  in 
each  end  and  fitted 
with  corks. 

Method.  —  Place 
three   candles    in   the 
box  as  shown  in  the 
accompanying    figure. 
Light  the   candles  so  as  to  use  up   the  oxygen. 

Observations.  —  With  all  the  corks  in  place,  how  long  (take 
exact  time)  do  the  candles  burn? 


PROBLKJM   21(;  215 

Remove  the  upper  corks  from  holli  ends.  II..\v  lonu  .l<>  flie 
candles  burn  ? 

Remove  the  lower  corks,     jlow  long  do  tlic  candles  burn? 

Remove  one  upper  and  one  lower  coik  fnun  one  end.  How 
long  do  the  candles  burn? 

Conclusion.  —  1.  What  is  the  best  method  of  ventilating  a 
room  ? 

2.  Make  cross-section  sketches  and  explain  the  difTerent  trials. 
Use  dotted  hues  and  arrows  to  represent  the  course  of  the  air. 

Problem,  215:  To  study  air  for  preHPncc  of  dust.  (Home  Ex- 
periment.) 

Materials.  —  Pan,  Petri  dish  with  sterile  culture  medium. 

Method.  —  1.  Sweep  a  rug  vigorously  with  a  dry  l)room.  Bru.-<h 
your  clothes  hard  after  returning  from  school.  2.  Phice  an  un- 
covered pan  of  water  where  a  draft  from  the  window  will  blow  over 
it.  3.  Place  a  sterile  culture  in  Petri  dish  on  window  sill  for  a  few 
moments  and  then  cover;  examine  after  five  days. 

Observations.  —  What  do  you  see  in  the  air?  What  do  you 
notice  on  the  surface  of  the  water?     What  grows  in  the  tlish? 

Conclusion.  —  What  is  in  the  air? 

Note.  —  a  home  experiment  with  culture  media  to  find  out  dust  conditions 
in  different  parts  of  a  city  would  be  of  much  interest  for  extra  credit  work.  Sug- 
gested places  for  exposure  of  Petri  dishes  would  he  (a)  a  dirty  street ;  ('<)  a  wi-U- 
swept  and  watered  street ;  (c)  a  city  park  ;  {d)  a  city  market ;  (f )  a  work.sljop ; 
(/)  the  top  of  a  tall  building.  Determine  by  means  of  colonies  formed  in  the  plate 
the  relative  numbers  of  bacteria  (and  probably  the  dust  content  of  the  air). 

Problem  216:  To  determhie  the  best  viethod  of  elediiin^  a 
room. 

Materials.  —  Culture  dishes,  dry  broom,  cloth,  carpc^t  sweeper, 
vacuum  cleaner.  Use  four  adjoining  schoolrooms  in  which  the 
dust  is  approximately  the  same.  Expose  culture  dishes  in  each 
room  a  given  length  of  time,  say  two  mimites,  while  sweeping. 
Sweep  room  1  with  a  dry  broom,  room  2  with  a  broom  ov(^r  which 
a  wet  cloth  has  been  fastened,  room  3  with  a  carpet  sweeju'r,  and 
in  4  use  a  vacuum  cleanei-.  Place  each  exj)osed  dish  uniler  the 
same  conditions  and  examine  after  2,  3,  4,  and  o  days. 


246 


RESPIRATION    AND   EXCRETION 


In  which  dish  has  the  greatest  number  of  colonies  developed? 
Conclusion.  —  1.    In   which   room    was    the    most    dust    (and 
bacteria)  stirred  up? 

2.  What  do  you  consider  the  best  method  of  cleaning  a  room? 

Problem  21 7 :  What  mahes  a  crowded,  closed  room  uncojn- 
fortahJe? 

NOTE.  —  It  has  recently  been  discovered  that  other  factors  besides  the  presence 
of  carbon  dioxide  in  the  air  of  a  room  make  it  uncomfortable.  A  little  thought  on 
the  following  questions  will  convince  you  of  this. 

Observations.  —  When  a  candle  burns,  what  is  given  off  be- 
sides carbon  dioxide?     When  a  number  of  people  are  in  a  closed 

room,  what  then  would  be  given  off  from  their 
bodies  ? 

Note.  —  The  use  of  a  wet  and  dry  bulb  thermometer 
in  a  closed  room  containing  people  will  show  a  decided  in- 
crease in  the  water  content  (humidity)  of  the  air. 

Where  does  this  water  come  from?  In 
what  condition  does  it  get  into  the  air  ? 

What  is  your  normal  temperature  ?  Is  that 
the  temperature  of  the  air  of  the  room? 
What  three  substances  are  given  off  from 
human  bodies  that  might  affect  the  air  of 
a  closed  room?  Are  you  more  comfortable 
on  a  hot  humid  day  or  on  a  hot  dry  day? 
What  similar  condition  exists  in  a  closed 
room? 

Note.  —  The  close  odor  noticeable  in  a  closed  room 
containing  people  is  due  to  certain  organic  wastes  given 
off  from  the  body  into  the  air. 


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A  Wet  and  Dry 
Bulb  Thermometer. 


Conclusion.  —  What  factors  cause  discomfort  in  closed  rooms 
where  there  are  many  people? 

Prohlein  218 :  To  study  the  structure  of  the  hidney. 

Material.  —  A  sheep  kidney. 

Method  and  Observations.  —  An  idea  of  the  internal  structure 
of  the  kidney  of  man  may  be  gained  by  examination  of  a  sheep's 


PROBLEM   210  247 

kidney.  Get  the  butcher  to  leave  the  mass  of  fat  around  the  kid- 
ney. Of  what  use  might  this  fat  be?  Notice,  after  removing  the 
fat,  that  the  kidney  appears  to  be  closely  wrapped  in  a  thin  coat 
of  connective  tissue;  this  is  called  the  capsule.  l{emove  the 
kidney  from  this  capsule.  Notice  its  color  and  shaiK\  The  de- 
pression called  the  hilwn  is  deeper  than  the  corresponding  region 
in  the  kidney  bean.  The  hollow  tube  passing  out  from  this  region 
is  called  the  ureter.  Blood  vessels  also  enter  and  leav(^  the  kidney 
at  the  hilum.  Cut  the  kidney  lengthwise  into  halves.  Try  to 
find  the  following  regions:  (1)  th(^  outer  or  cortical  region;  note 
its  color;  (2)  the  inner  or  medullanj  layer;  this  layer  is  provided 
with  little  projections ;  these  are  the  pyramids  of  Malpighi,  so 
called  after  their  discoverer,  Marcello  Malpighi,  a  celebrated 
Italian  physiologist;  (3)  the  cavity  or  pelvis  of  the  kidney.  At 
the  summit  of  each  pyramid  is  a  small  opening  through  which 
escapes  into  the  pelvis  the  secretion  formed  in  the  little  tubules 
in  which  the  real  work  of  excretion  is  performed. 

Conclusion.  —  1.  Where  is  the  waste  taken  from  the  blood  in 
the  kidney?     (Study  the  diagram  on  page  341,  Ciric  Biology.) 

2.    Where  does  this  waste  pass  out  of  the  body? 

Problem  219:  The  shin  as  an  or^an  of  exeretion  and  heat 
control. 

Materials.  —  Model  of  human   skin   in  section,  tliermometers, 

hand  lens,  jars,  scales. 

a.  Structure 

Method.  —  Examine  the  model  of  a  cross  section  of  skin. 
Locate  (using  your  Civic  Biology,  page  342)  the  (»i)idermis, 
dermis,  sweat  glands,   oil  glands,   nerves,  and   blood  vessels. 

Observations.  —  Where  is  the  epidermis  and  what  structures 
does  it  contain?  Examine  the  surface  of  your  skin  with  a  hand 
lens.     What  structures  are  found  in  the  dermis? 

Conclusion.  —  How  might  the  above-mentioned  structures   be 

of  value  to  the  body? 

b.  Functions 

The  above  question  may  be  answered  in  part  by  the  following 
experiments  made  at  home  or  in  the  laboratory. 


248 


RESPIRATION   AND   EXCRETION 


1.  Method.  —  Insert  your  hand  in  a  clean,  dry  fruit  jar.  Wrap 
a  towel  over  the  opening  of  the  jar  so  as  to  allow  no  air  to  get  in 
between  your  hand  and  the  sides  of  the  jar. 

Observations.  —  What  happens  in  the  jar? 
Conclusion.  —  What  is  given  off  from  the  hand? 

2.  Method.  —  Weigh  yourself.  Note  the  weight.  Exercise  vi- 
olently for  half  an  hour ;  weigh  yourself  again.     Note  the  weight. 

Observations.  — Was  there  any  change  in  weight? 

Conclusion.  —  How  must  the  change  of  weight  have  been 
brought  about  and  how  did  the  body  lose  this?  Remember  that 
when  oxidation  of  food  or  tissue  takes  place  in  the  body  three 
products,  at  least,  are  formed :    heat,  organic  wastes,  and  water. 

(Food  +  oxygen  =  carbon  dioxide  +  water  +  organic  wastes  +  heat 
+  muscular  energy.) 

3.  Method.  —  Take  the  temperature  of  the  body  before  and 
after  exercise  by  placing  a  clinical  thermometer  in  the  mouth. 
Any  change?     Account  for  this  by  the  following  experiment. 

4.  Method.  —  Take  two  thermometers,  place  a  damp  cloth 
around  the  bulb  of  one  and  leave  the  other  exposed  without  a 
damp  cloth.  After  some  time,  so  as  to  allow  the  water  in  the 
cloth  to  reach   the  same  temperature  as  the  air  in  the  room, 

read  the  two  ther- 
mometers. 

Observations.  — 
Do  they  both  read 
the  same?  How  do 
you  account  for  the 
difference?  Remem- 
ber that  when  water 
evaporates,  it  takes 
heat  from  the  air  sur- 
rounding it. 

Conclusion.  —  Ap- 
plying this  principle 
to  the  skin,  explain 
why  evaporation  from  the  skin  makes  us  feel  cooler. 


Income  of  blood 

Org'aiv 

Outgo  o/klood  to 

A.1  ll«  e.T\.tary  Canal 

5^ofrorn  Small  Intestine 

Ti  S  S wes 

Muscle.  Nerve .  l>oive 

Li-v  er» 

I<  x^ixgs 

Ki^»\e^.s 

^ki  IX 

PUOBLKAI   (21:KSTI()XS  2\\) 

General  Conclusion.  —  Explain  Ihc  functions  of  the  skin  in  the 
light  of  the  above  experiments. 

The  skin  as  an  or^an  of  sensation  will  1k>  treated  later. 

Fill  out  the  foregoing  sunnnary  of  changes  taking  place  in  Lln^d 
within  the  organs  of  the  body. 

Problem   Questions 

1.  How  are  the  lungs  fitted  to  do  their  work? 

2.  How  is  oxygen  of  use  to  th(^  body? 

3.  Show  two  means  by  which  oxygen  is  taken  into  the  lungs. 

4.  Why  should  we  practice  deep  breathing  exercises  each 
day? 

5.  What  habits  of  bad  posture  harm  the  lungs ?  Explain  ^our 
answer. 

6.  What  changes  take  place  in  the  blood  within  the  lungs? 

7.  What  changes  take  place  in  air  within  the  lungs? 

8.  What  is  given  off  in  the  air  from  the  lungs  as  a  result  of  oxi- 
dation ? 

9.  What  is  oxidation?  Where  does  it  take  place  in  the  human 
body? 

10.  Show  exactly  how  oxygen  reaches  the  cells  of  the  body. 

11.  What  does  a  cell  do  as  a  result  of  oxidizing  food? 

12.  Why  should  people  sleep  with  windows  open? 

13.  Make  a  diagram  to  show  how  to  ventilate  a  room. 

14.  How  would  you  ventilate  through  a  window  without  making 
a  draft? 

15.  Can  you  explain  the  school  system  of  ventilation'.'  Is  it  a 
good  one?  (Remember  that  hot  aii-  ris(>s  and  takes  uj)  with  it 
carbon  dioxide.) 

16.  Explain  the  advantage  of  using  damp  sawdust  when  sweep- 
ing. 

17.  How  would  you  prevent   dust    in   a  sl(M»ping   room?    In   a 

schoolroom  ? 

18.  Which   is  cleaner,  a   paved   or  an   uni):i\e(|   <tre(>f".*     Why'.' 

19.  Why  is  street  sprinkling  a  g(K)d  thing? 

20.  Which  is  most  cleanlv  :  n  lamp,  gas,  or  el(>ctricit y'.'     Why? 


250  RESPIRATION   AND   EXCRETION 

21.  What  are  the  advantages  of  the  vacuum  cleaner  over  other 
forms  of  sweepers? 

22.  How  can  you  tell  when  the  air  of  a  room  becomes  bad? 

23.  Why  should  considerable  water  be  drunk  every  day? 

24.  Of  what  use  is  perspiration  to  the  body? 

25.  How  would  you  keep  the  skin  clean? 

26.  Give  facts  to  prove  that  the  skin  gives  off  waste  products. 

27.  What  is  the  relation  of  the  heat  of  the  body  to  work  done 
by  the  body? 

28.  What  is  the  physiological  use  of  (a)  the  cold  bath,  (6)  a 
moderate  bath,  and  (c)  a  hot  bath? 

29.  Why  do  we  feel  more  oppressed  on  a  hot  humid  day  than  on 
a  hot  dry  day? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XXII.     American  Book  Company. 

Hunter,  Elements  of  Biology,  Chaps.  XXIII,  XXIV.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XXVII.     American  Book  Company. 

Baum,  Conscious  Control  of  the  Diaphragm.     Musician,  May,  1914. 

Brady,  How  He  Held  His  Breath.     Technical  World,  July,  1914. 

Conditions  Inducing  Excessive  Respiration.     Scientific  American,  July  11,  1914. 

Davison,  Human  Body  and  Health.     (Advanced.)     American  Book  Company. 

Gulick,  Hygiene  Series,  Emergencies,  Good  Health.     Ginn  and  Company. 

Hough  and  Sedgwick,  The  Human  Mechanism.     Ginn  and  Company. 

Howell,  Textbook  of  Physiology.     The  Macmillan  Company. 

Long,  Physiological  Chemistry.     P.  Blakiston's  Son  and  Company. 

Macy,  General  Physiology.     American  Book  Company. 

Ritchie,  Human  Physiology.     World  Book  Company. 


XXIIL     BODY   CONTROL   AND    HABIT    FOHMATIoX 

Problems.  —  How  is  body  control  viaiiihiin^fl  ? 

(a)    W]iat  is  tlie  niecJiauisDi  of  dirertioti  and  control? 

{h)    What  is  the  inetliod  of  direction  and  control  / 

(c)  Wh  at  are  habits  ?    How  are  they  formed  and  Ji  otr  broken  ? 

(d)  What  are  tJw  organs  of  sense  ?     What  are  their  uses? 

(e)  How  does  alcohol  affect  the  nervous  system  ? 

Laboratory  Suggestions 

Demonstration.  —  Sensory  motor  reactions. 

Demonstration.  —  Nervous  system.     Models  and  frop:  dissections. 

Demonstration.  —  Neurones  under  compound  microscope  (optional). 

Demonstration.  —  Reflex  acts  are  unconscious  acts ;  show  how  con- 
scious acts  may  become  habitual. 

Home  exercise  in  habit  forming. 

The  senses.  —  Home  exercises.  —  (1)  To  determine  areas  most  sensitive 
to  touch.  (2)  To  determine  or  map  out  hot  and  cold  spots  on  an  area  on 
the  wrist.      (3)  To  determine  functions  of  different  areas  on  tongue. 

Demonstration.  —  Show  how  eye  defects  are  tested. 

Laboratory  summary.  —  The  effects  of  alcohol  on  the  nervous  system. 

To  THE  Teacher.  —  The  purposes  of  the  followinK  e.xerrises  are  first,  to  show 
the  pupil  that  he  is  dependent  upon  his  organs  of  sense  in  order  to  interpret  what 
goes  on  about  him,  thus  to  get  in  touch  with  the  factors  of  his  environment ;  second, 
to  give  him  a  gUmpse  of  the  great  complexity  of  the  mechanism  and  complicated 
structure  we  call  the  nervous  system  ;  third,  to  show  him  liow  habit  might  \yo 
evolved  and  the  part  habit  plays  in  our  daily  life;  and  lastly,  a  slight  conception 
of  the  workings  of  the  organs  of  sense,  as  shown  by  experimental  psychology. 

Problem  220 :  How  are  we  aware  of  the  ivorld  aJmiit  us  ? 

Materials.  —  Needle,  ether  or  freezing  mixture  for  local  aiuesthe- 
sia,  various  substances  having  distinct  taste. 

Method  and  Observations. — Touch  a  flat  and  a  rou^li  surface 
with  the  finger  tips. 

Prick  yourself  with  a  needle.  Then  place  a  drop  of  ether  or 
freezing  mixture  on  the  same  finger  and  prick  it.  Do  you  still 
feel?     How  do  you  explain  the  dilTerence? 

251 


252      BODY   CONTROL   AND   HABIT   FORMATION 

Close  your  eyes  and  allow  some  one  to  place  bits  of  various 
substances  on  your  tongue.  Can  you  distinguish  between  the 
(hfferent  substances? 

Look  at  this  page.  How  do  you  get  your  knowledge  of  what  is 
on  this  page? 

At  how  great  a  distance  can  you  hear  a  watch  tick? 

Conclusion.  —  Through  what  organs  do  we  become  aware  of 
the  world  around  us? 

Problem  2'41 :  To  determine  what  parts  of  the  hody  are  most 
sensitive  to  {a)  touch,  (b)  heat  and  cold. 

a.  Touch 

Materials.  —  Compass. 

Method  and  Observations.  —  Blindfold  a  pupil.  Then  lightly 
touch  the  back  of  his  hand  with  the  two  points  of  a  compass. 
Begin  with  them  close  together  and  gradually  move  them  apart. 
Have  the  blindfolded  subject  tell  as  soon  as  the  points  appear  to 
the  touch  as  two.  Experiment  further  on  different  parts  of  the 
body,  and  record  the  results  in  the  form  of  a  table. 


Place  TovccKed. 

DistanceJjetween  Poiivts 

Bcick  of    ticLYxd 

PcxIttv  ^    Hccivd 

I^ixvgei»    Tip^ 

^A7'^i^i: 

ULpper'   A.x»xxv 

RctcK  o^!Neclk 

Bcrck 

- 

Conclusion, 
to  touch? 


Which  part  of  the  body  seemed  most  sensitive 


b.  Heat  and  Cold 


Materials.  —  Large  wire  nail,  pen,  ink,  and  ruler. 
Method  and  Observations.  —  With  a  ruler  and  a  pen,  draw  a 
square  inch  on  the  under  side  of  your  wrist.     Heat  a  wire  nail  so 


PUOBLEIVI    222  2:).\ 

it  feels  very  warm.  Now  lightly  touch  all  parts  of  the  skin  within 
the  square  area.  Do  all  parts  feel  the  heat,  or  only  the  sense  of 
sHght  pressure  of  the  nail?  Mark  witli  a  little  cross  all  spots 
that  are  sensitive  to  heat. 

Now  cool  off  the  nail  by  placing  it  on  ice.  \\ij)c  it  diy  and  a|)j)ly 
while  still  cold  in  the  same  way  to  the  area  marked  off  on  the 
wrist.  Do  you  feel  the  sensation  of  cold  in  all  spots?  Mark 
as  before,  this  time  using  a  dot. 

Note.  —  Certain  sense  cells  of  the  body  are  sensitive  to  heat,  others  to  cold. 

Conclusion.  —  1.  Do  these  sense  cells  occupy  the  same  area? 
2.  Do  all  parts  of  the  skin  feel  heat  and  cold  ? 

Problem  222 :  To  study  the  anatoinij  of  the  nervous  si/stem. 

Materials.  —  Frogs  preserved  in  formalin,  with  body  cavity 
opened  and  viscera  removed,  scissors,  scalpels,  forceps,  hand  lens, 
charts  showing  nervous  system  of  man,  model  of  Ijrain  of  man. 

Method.  —  In  a  frog  from  which  the  organs  of  the  body  cavity 
have  been  removed,  note  white  glistening  cords  {nerves)  which 
seem  to  come  from  under  the  backl)one.  Follow  the  cour.^e  of 
some  of  the  larger  nerves.  Where  do  they  lead?  Now  turn  the 
frog  over  and  with  sharp  scissors  and  a  scalpel  remove  very  eare- 
fully  the  bony  covering  (the  skull)  from  the  whitish  body  (the 
brain). 

Observations.  —  How  many  parts  do  there  ai)i)(nir  to  be  in  the 
brain?  Notice  the  white  elongated  hemisphere  of  the  fore  brain 
or  cerebrum.  The  two  anterior  projections  of  the  cerebrum  are 
called  olfactory  lobes.  Where  do  these  lobes  seem  to  lead? 
What  do  you  think,  from  the  name,  their  use  is? 

Just  back  of  the  cerebrum,  find  two  large  lobes,  known  as  ()i)tic 
lobes,  which  have  to  do  with  sight.  Look  at  the  chart.  Are 
the  eyes  connected  with  the  optic  lobes?  Hack  of  the  optic 
lobe  we  find  the  cerebellu7n  and  mednlUi,  the  latiei-  ruiming  directly 
into  the  spinal  cord,  from  which  rise  the  s|)inal  nerves  you  have 
noted  before. 

Compare,  part  by  part,  the  brain  of  the  fiog  with  the  model  of 
the  brain  of  man. 


254      BODY   CONTROL  AND   HABIT   FORMATION 

Conclusion.  —  1.  In  what  respect  is  the  frog's  nervous  system 
like  that  of  man?     How  does  it  differ? 

2.  Write  a  description  comparing  the  nervous  system  of  the 
frog  with  your  own,  using  charts  and  models  as  a  guide. 

Problem  223 :  To  study  the  structure  and  use  of  neurons. 

Method.  —  Study  the  figure  on  page  351,  Civic  Biology.  The 
cell  pictured  is  known  as  a  neuron  or  a  unit  of  the  nervous  system. 
The  brain  and  spinal  cord  contain  many  millions  of  them.  One 
end  of  a  neuron  may  be  in  the  brain  and  the  other  end  far  away 
in  the  spinal  cord ;  or  one  end  may  be  near  the  surface  of  the 
body  and  the  other  end  in  the  spinal  cord  or  brain. 

Observations.  —  How  do  these  cells  compare  in  length  with 
other  cells  of  the  body  ? 

NOTE.  —  If  a  neuron  has  for  its  function  the  sending  of  messages  from  within 
outwards  (to  muscles),  it  is  a  motor  nerve.  If  it  receives  stimuli  from  without,  it  ia 
a  sensory  nerve. 

Conclusion.  —  AVhat  structures  in  the  nervous  system  carry 
the  impulses  from  the  surface  to  the  brain?  From  the  brain 
to  the  muscles  or  other  parts  of  the  body? 

Problem  224 :  What  is  a  reflex  action  ? 

Method  and  Observations.  —  If  somebody,  without  warning, 
pretends  to  strike  you  in  the  face,  what  happens?  Through 
.  what  parts  of  the  nervous  system  would  you  become  aware  of 
what  was  happening? 

With  your  eyes  closed  touch  a  hot  surface.  What  happens? 
Did  you  think  about  withdrawing  your  hand? 

Conclusion.  —  1.  Actions  of  the  sort  just  described  are  called 
reflexes.  Explain  as  well  as  you  can,  using  the  figure,  the  path- 
way of  a  reflex  action. 

2.  Does  this  pathway  reach  the  cerebrum  or  thinking  part  of 
the  brain? 

Problem,  225 :  To  compare  the  reaction  time  of  hearing  and 
touch. 

Method  and  Observations.  —  Let  the  class  form  a  large  circle 
and  then  start  a  whispered  word  at  one  end  of  the  circle.     Let  the 


]M^)HLI:M    227 


2.j3 


teacher  note  the  number  of  seconds  for  tlie  word  to  got  hack  to 
the  startmg  point.  By  dividmjj;  this  tune  hy  tlic  total  niniihcr  of 
participants  the  average  reaction  tune  for  hearing  of  i\w  class  can 
be  obtained. 

Now  let  members  of  the  class  just  touch  finger  tips.  In  the  same 
manner  as  in  the  previous  experiment,  let  the  Instructor  start  a 
signal  (a  short  pressure  of  the  fingers).  (let  ihc  average  reaction 
time  as  in  the  previous  experiment. 

Conclusion.  —  Which  gives  a  quicker  reaction,  hearing  or  touch? 

Problem  226:  To  coni/)are  a  reflex  (iHion  with  an  act  of 
tliought. 

Method.  —  Using  the  figures  note  the  pathway  with  relays 
of  cells  between  the 
eye  when  you  see  a 
book,  and  the  rest 
of  the  nerves  in- 
volved when  you  de- 
termine  to  pick  it  up 
and  do  so. 

Observations.  — 
Make  a  diagram 
showing  the  path- 
way. Compare  this 
pathway  with  the 
one  taken  when  you  touch  your  hand  against  a  hot  stove  in  the 
dark. 

Conclusion.  —  What  is  the  chief  difference  in  the  nervous  path- 
way between  a  reflex  and  an  act  of  thought? 

Problem  227  '  To  study  habit  forming. 

Note.  —  a  little  chick  just  hatched  in  an  incubator  picks  at  food.  It  has  no 
mother  to  teach  it.  Such  an  act  i.s  called  instinctiit:.  It  is  an  act  arcouiplished 
without  reasoning.  When  a  new-born  baby  sucks,  its  act  is  also  instinctive. 
Upon  such  instincts  life  depends. 

Observations.  —  When  a  baby  is  just  learning  to  walk,  tlu^  first 
step  would  probably  be  brought  about  by  its  reaching  or  stretcii- 


An  Involuntary  Act. 


256      BODY   CONTROL   AND   HABIT   FORMATION 

ing  for  something  it  wanted.  This  would  in  a  way  be  an  instinc- 
tive act.     Can  you  explain  how? 

When  you  first  learned  to  write,  did  you  think  about  making 
the  letters  of  the  words  you  wrote?  Do  you  now?  How  do  you 
account  for  the  ease  with  which  you  now  write? 

What  is  the  chief  difference  between  the  instinctive  act  of  the 
baby  learning  to  walk  and  the  act  of  writing?  Do  we  think  about 
writing  now  ?  Did  we  think  about  it  when  we  began  to  learn  ? 
An  act  consciously  repeated  many  times  eventually  becomes  a 
hahit.  Might  a  habit  be  formed  through  the  unconscious  repeti- 
tion of  an  act? 

Conclusion.  —  1.  What  is  an  instinct? 

2.  What  is  a  habit?     How  might  it  be  formed? 

3.  What  is  the  difference  between  instinct  and  hal:)it  ? 


Problem  228 :  To  study  the  mechanisin  of  hahit  formation. 

Note.  —  The  formation  of  a  habit  involves  the  simplifying  of  a  complicated 
process.     In  an  act  of  thought,  e.g.,  picking  up  a  toothbrush  from  the  washstand  (see 

diagram)  the  eye  sees  the  brush  and  relays  the 
message  through  some  sight  cells  to  a  nerve  center 
in  the  back  of  the  brain  {O.C^.  From  there  the 
message  is  again  relayed  to  (M.C),  where  the 
impulse  is  originated  to  pick  the  brush  up.  This 
results  in  a  message  being  sent  by  another  relay 
of  several  sets  of  cells  down  the  spinal  cord  to 
the  muscles  of  the  arm  where  the  fibers  from  this 
neuron  end  in  the  muscles. 

Now  if  the  act  becomes  habitual,  as  it  does 
when  we  brush  our  teeth  each  morning,  the 
stimulus  caused  by  the  sight  of  the  brush  causes 
a  short  circuit  of  the  impulse  which  goes  to  O.C. 
and  then  directly  down  the  spinal  cord. 


The    Course    taken   by  the 
Act  of  Thought. 

O.C.^    nerve    center;    M.C., 
thought  center. 


Conclusion.  —  1.  If  M.C.  is  the 
thought  center,  then  what  does  habit 
forming  do? 

2.  Would  it  be  better  to  make  a 
problem  of  brushing  your  teeth  each  morning  or  to  do  it  auto- 
matically (by  habit)  ? 

3.  Just  how  is  a  habit  formed  in  the  nervous  center? 

4.  Of  what  advantage  are  habits  ? 


PR0BTJ-:M   2:10  257 

Problem  2'iiP  :  To  consider  sonir  litwiiifiiJ  Jidhifs. 

a.  Tobacco 

Method.  —  Allow  the  smoke  from  half  a  dozen  eiKarettes  {o 
pass  through  the  water  of  a  small  jai-  eontaiiiing  a  gcjldlish,  or 
add  a  small  piece  of  tobacco  to  the  water. 

Observations.  —  What  is  the  result? 

Conclusion.  —  Might  tobacco  liavc  any  similar  elTect  on  other 
living  things,  as  man? 

b.  Alcohol 

Method  and  Observations.  —  Using  the  figures  given  \\\  your 
Civic  Biology,  on  pages  363,  369,  370,  371,  explain  why  life  insur- 
ance companies  consider  moderate  drinkers  an  extra  risk. 

Conclusion.  —  What  effect  does  the  drink  habit  have  upon 
man? 

Problem  230 :  How  to  go  to  work  to  form  good  habits. 

Method  and  Observations.  —  Study  the  following  statement  : 
"  The  hell  to  be  endured  hereafter,  of  which  theology  tells,  is  no 
worse  than  the  hell  we  make  for  ourselves  in  this  world  1)\-  ha- 
bitually fashioning  our  characters  in  the  wrong  way.  Could  the 
young  but  realize  how  soon  they  will  become  mere  bundles  of  h(d>its, 
they  would  give  more  heed  to  their  conduct  while  in  the  plastic  state. 
We  are  spinning  our  own  fates,  good  or  evil,  and  never  to  be  undone. 
Every  smallest  stroke  of  virtue  or  of  vice  leaves  its  never-so-little 
scar.  The  drunken  Rip  Van  Winkle,  in  JefTerson's  play,  excuses 
himself  for  every  fresh  dereliction  b}'  saying,  '  1  won't  count  this 
time.'  Well!  he  may  not  count  it;  but  it  is  being  counti'd  none 
the  less.  Down  among  his  nerve  cells  and  fibers  the  molecules 
are  counting  it,  registering  and.  storing  it  up  to  be  used  against  him 
when  the  next  temptation  comes.  Nothing  we  ever  do  is,  in  strict 
scientific  literalness,  wiped  out.  Of  course  this  has  its  good  >ide 
as  well  as  its  bad  one.  As  we  become  permanent  drunkards  by 
so  many  separate  drinks,  so  we  become  saints  in  the  moral,  and 
authorities  in  the  practical  and  scientific  spheres,  by  so  many 
separate  acts  and  hours  of  work.  Let  no  youth  hare  any  anxiety 
about  the  upshot  of  his  education  whatever  the  line  of  it  nuiy  be.     If 

HUNTER   LAB.    PUGB. 17 


258      BODY   CONTROL   AND    HABIT   FORMATION 

he  keeps  faithfully  busy  each  hour  of  the  working  day,  he  may  safely 
leave  the  final  result  to  itself.  He  can  with  perfect  certainty  count 
on  waking  up  some  fine  morning,  to  find  himself  one  of  the  competent 
ones  of  his  generation,  in  whatever  pursuit  he  may  have  singled  out." 
—  James,    Psychology. 

Man  is  thus  shown  to  be  a  bundle  of  appetites. 

Conclusion.  —  1.  What  are  the  best  ways  of  forming  good  habits 
and  continuing  to  observe  them?  Write  a  short  composition  on 
this  important  subject. 

2.  How  should  one's  judgment  and  appetite  relate  to  each 
other  ? 


Problem  231 :  To  determine  the  relation  hetween  taste  and 
smell  with  reference  to  food  flavors. 

Materials.  —  Vegetables,  spices,  flavors. 

Method.  —  Close  the  eyes  and  hold  nose  tightly  with  one  hand; 
with  the  other  place  on  the  tongue  pieces  of  peeled  apple,  peeled 
raw  potato,  peeled  raw  turnip,  and  onion.  Have  the  pieces 
exactly  the  same  taste?  Have  some  one  record  the  results. 
Are  you  aware  of  the  different  flavors?  Are  you  with  the  nos- 
trils  open?     Experiment   with   a   number   of   other   substances, 

as  sugar,  vinegar,  va- 
nilla, mustard,  salt, 
spices,  etc.,  holding 
nose  and  closing  eyes. 
Rub  the  tongue  dry. 
Place  a  little  sugar  on 
it.  In  what  condition 
must  materials  be  in 
order  to  be  tasted? 

Observations.  —  In 

tabular    form    note 

those     substances 

which  are  learned  by  taste  only  and  those  which  are  recognized 

by  taste  and  smell. 

Conclusion.  —  What  is  the  relation  of  taste  and  smell  in  dis- 
tinguishing flavors? 


EecogTvized 
by  Taste 

Kecogrnixed 
by  Smell 

Apple 

Onioix 

Potato 

Xu  rrvlp 

Salt 

SxA  0a  I- 

>lnstard 

Varvilla 

Virvegar 

PROBLK.M   2:V.]  250 

Problem  V/iV  ;  Ifow  to  find  out  cerfnin  t/cfcrfs  of  vision  in  the 
laboratory. 

Materials.  —  Schnellen's  test  cards,  spoctiiclcs  with  diopter 
lenses,  clock  dial  chart. 

a.  Test  for  Farsightedness 

Method.  —  Using  the  Schnellen's  test  caids,  locate  the  finest 
line  that  can  be  read  at  a  distance  of  20  feci.  Test  each  eye 
separately,  covering  the  eye  not  in  use  with  a  piece  of  card  hoard. 
Then  place  a  pah'  of  spectacles  witli  a  50  phis  diopter  lens  before 
the  eyes.  If  as  fine  or  a  finer  line  can  now  be  read,  tlien  far- 
sightedness is  present  and  an  oculist  should  ])e  consulted,  espe- 
cially if  headaches  or  other  symptoms  of  eye  defects  are  present. 
Farsightedness  is  one  of  the  most  frequent  causes  of  eyestrain  and 
is  hard  to  detect  because  the  eyesight  seems  so  good. 

b.  Test  for  Nearsightedness 

Method.  —  Use    the   above-mentioned  charts.     Determine  the 

finest  type  you  can  read  at  a  distance  of  20  feet.     If  it  is  larger 

than  the  20/20  line,  then  your  vision  is  defective  and  you  should 

probably  consult  an  oculist,  especially  if  you  have  an>-  symptoms 

of  eyestrain. 

c.   Test  for  Astigmatism 

Method.  —  Use  the  clock  dial  disk  at  20  feet.  If  some  lines  are 
blacker  than  others,  then  astigmatism  is  present.  If  headaches 
or  other  symptoms  are  present,  then  you  should  consult  an  oculist 
and  have  glasses  fitted  to  correct  this  trouble. 

Next  examine  a  chart  or  model  of  tlu^  human  eye  and  deter- 
mine what  defects  must  occur  within  yoiu-  eye  to  cause  the  defects 
in  vision  you  have  found.  (Your  teacher  will  I'xplain  the  terms 
''  nearsightedness,  farsightedness,  and  astigmatism.") 

Conclusion.  —  Have  I  anv  eve  defects?  If  so.  what  are  ihfv, 
and  how  nmst  I  go  about  to  correct  them? 

Problem  23:i :  What  are  some  of  the  efferts  of  aJrohol  on  the 
nervous  system  ? 

Method.  —  Using  the  figures  on  pages  'MY.],  305,  300,  30i).  :>70.  37 1 . 
372,  Civic  Biology,  make  a  graph  to  show  the  elTect  of  alcohol  upon 


260      BODY  CONTROL  AND   HABIT   FORMATION 

memory,  mental  work,  ability  to  do  physical  work,  efficiency,  acci- 
dents. 

Conclusion.  —  1.  What  effect  does  alcohol  have  upon  the  nervous 
system  ? 

2.  Write  a  short  composition  on  this  subject. 

Problem  Questions 

1.  Do  you  suppose  the  neurons  of  a  child  just  learning  to  walk 
find  it  easy  to  send  out  exactly  the  right  orders  to  the  muscles? 
Explain  your  answer. 

2.  Do  you  consciously  think  about  making  steps  when  you 
now  walk?     Why  not?     (Consult  chart.) 

3.  In  learning  to  do  anything  in  concert,  how  does  the  first  re- 
hearsal compare  with  the  last  ? 

4.  What  is  a  necessary  factor  in  forming  a  habit?  Remember 
that  pathways  become  worn  along  certain  lines  so  that  the  neurons 
in  those  pathways  take  up  the  work  instinctively. 

5.  Explain  this  story:  ''A  practical  joker  saw  a  discharged 
veteran  carrying  his  dinner  home  and  suddenly  called  out,  '  Atten- 
tion ' ;  whereupon  the  veteran  instantly  brought  his  hands  down, 
dropping  his  dinner  in  the  gutter." 

6.  What  is  the  advantage  of  forming  good  habits  in  life? 

7.  Does  habit  forming  throw  work  off  part  of  the  nervous  sys- 
tem?    Explain  fully. 

8.  How  are  habits  formed  ? 

9.  Write  a  paragraph  on  the  increased  effectiveness  and  power 
acquired  through  good  habits. 

10.  Is  it  easy  to  break  a  habit?     Explain  your  answer. 

11.  Why  is  a  grammar  school  idler  quite  likely  to  continue  to 
be  an  idler  in  high  school,  and  a  high  school  idler  a  college  idler  ? 

12.  Why  are  the  railroads  requiring  their  employees  to  abstain 

from  liquor? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XXIII.     American  Book  Company. 
Hunter,  Elements  of  Biology,  Chap.  XXXV.     American  Book  Company. 
Hunter,  Essentials  of  Biology,  Chap.  XXVIII.     American  Book  Company. 
Angell,  Psychology.     Henry  Holt  and  Company. 


I 


Berol,  System  of  Memory  Training.     Funk  and  Wannalls  Coiupany. 

Brewer,  Rural  Hygiene.     J.  H.  Lippinoott  Company. 

Brown,  Good  Health  and  Long  Life,      Published  by  autlior  Dr.  W.  Brown.  ('liicnKO. 

Clouston,  Hygiene  of  the  Mind.     Unsoundness  of  Mind.     K.  P.  I)uttf)ii  .-in*!  Com- 
pany. 

Cook,  Health  through  Rational  Living.     D.  C.  Cook  Puhli.shinj?  C'ompany. 

Dotey,  Prevention  of  Nervous  Diseases.     D.  Applet(jn  and  Company. 

Du  Bois,  Self  Control  and  How  to  Control  H.     Funk  and  Wagnalls  Company. 

Eyestrain  from  Movie  Habit.     Literary  Digest,  May  'M),  1914. 

Forel,  Hygiene  of  Nerves.     G.  P.  Putnam's  Sons. 

Gordon,  Modern  Mother.     Fenno  and  Company. 

Gulick,  Mind  and  Work.     Doubleday,  Page  and  Company. 

Gulick,  Control  of  Mind  and  Body.     Ginn  and  Company. 

Gulick,  The  Will  to  be  Cheerful.     World's  Work,  July,  1908. 

Hartman,  First  Book  of  Health.     World  Book  Company. 

Hope  and  Browne,  A  Manual  of  School  Hygiene.     G.  P.  Putnam's  Sons. 

Hough  and  Sedgwick,  The  Human  Mechanism.     Ginn  and  Company. 

Human   Being   without    Cerebral   Hemispheres.     Scientific  American,  Decemlxr    13, 
1913. 

Hutchinson,  Civilization  and  Health.     Houghton  Mifflin  Company. 

James,  Psychology,  Chap.  X.     Henry  Holt  and  ComiJany. 

Johnston,  What  Science  Has  Done  for  the  Child.     The  Designer,  March.  1910. 

Little  Danger  of  Brain  Strain.     Literary  Digest,  April  11,  1914. 

McCabe,  Evolution  of  Mind.     A.  and  C.  Black,  London. 

McComb,  Alcoholism,  Its  Causation  and  Its  Arrest.     Everybody's  Magazine,  .\pril, 
1909. 

McComb,    Nervousness,    A    National   Menace.     Everybody's    Magazine,    February, 
1910. 

Nervousness.     Review  of  Reviews,  January,  1914. 

Overton,  General  Hygiene.     American  Book  Company. 

Partridge,  The  Nervous  Life.     Sturgis  and  Walton. 

Paton,  Nervous  and  Chemical  Regulators  of  Metabolism.     The  Macmillan  Company. 

Ritchie,  Human  Physiology.      World  Book  Compan\-. 

Roddy,  Hygiene.     J.  A.  Roddy,  Philadelphia. 

Rowe,  Habit  Formation  and  the  Science  of  Teaching.     Longmans.  Green  and  Com- 
pany. 

Saleeby,  Worry,  the  Disease  of  the  Age.     F.  A.  Stokes  Company. 

Stiles,  Nervous  System  and  its  Conservation.     W.  B.  Saunders. 

Supplemeid  to  the  Brain.     Literary  Digest,  .March  14.  1914. 
Walton,  Why  Worry?     J.  B.  Lippincott  C«»mi)any. 
Ward,  Problem  of  Instinct.     Independent,  ,\uKUst  24.  1914. 
Worry,  Its  Cause  and  Cure.     Harper's  Bazar,  January.  1910. 


XXIV.   MAN'S   IMPROVEMENT   OF   HIS   ENVIRON- 
MENT 

Problems.  —  How  may  we  improve  our  home  conditions  of 
living  f 

How  may  we  help  improve  our  conditions  at  school  ? 

How  does  the  city  care  for  the  improvement  of  our  environ- 
ment ? 

(a)  In  inspection  of  buildings,  etc. 

(b)  In  inspection  of  food  supplies. 

(c)  In  inspection  of  milk, 
id)  In  care  of  water  supplies, 
(e)  In  disposal  of  wastes, 
if)  In  care  of  public  health. 

Laboratory  Suggestions 

Home  exercise.  —  How  to  ventilate  my  bedroom. 

Demonstration.  —  Effect  of  use  of  duster  and  damp  cloth  upon  bac- 
teria in  schoolroom. 

Home  exercise.  —  Luncheon  dietaries. 

Home  exercise.  —  Sanitary  map  of  my  own  block. 

Demonstration.  —  The  bacterial  content  of  milk  of  various  grades  and 
from  different  sources. 

Demonstration.  —  Bacterial  content  of  distilled  water,  rain  water,  tap 
water,  dilute  sewage. 

Laboratory  exercise.  —  Study  of  board  of  health  tables  to  plot  curves 
of  mortality  from  certain  diseases  during  certain  times  of  year. 

Note  to  Teachers.  —  The  exercises  which  follow  are  intended  to  be  suggestive 
and  may  be  extended  indefinitely  as  time  may  permit.  To  make  this  work  of 
most  value,  as  much  collateral  reading  as  can  well  be  made  available  should  be  used 
in  addition  to  the  definitely  planned  home  and  laboratory  work  outlined  in  the 
following  chapter.  Field  work  is  of  especial  importance  in  this  connection  as  it 
shows  the  pupils  what  the  city  departments  arc  doing  toward  the  inspection  of 
factories,  care  of  food  supplies,  inspection  of  milk,  both  in  production  and  in  the 
sale,  provision  for  a  safe  and  ample  water  supply,  disposal  of  wastes  and  care  of  the 
public  health.     An  effort  should  be  made  to  have  each  pupil  procure  a  copy  of  the 

262 


PR()BLr:AI  2:35  2fi:i 

Sanitary  Code  of  the  city  in  which  lie  lives  and  then  l)y  careful  study  to  hco  which 
sections  are  commonly  broken  and  honored  in  the  hrearh  hy  the  \h>\\vv>  or  health 
officials.  Concerted  action  on  the  part  of  tlie  younyer  niend)or«  of  u  conmiunity 
may  bring  about  decided  results  for  the  l)etternjent  of  a  ^iven  neinhlxirhood.  Thu» 
our  biology  courses  may  become,  in  truth,  courses  in  rivir  f>i»l»uy. 

Problem  234:  How  to  ventilate  nnj  bedroom.     (Ih.ine  Prr»blein.) 

Note.  —  This  problem  varies,  depending  on  llu-  nuinl)tT  and  iM).sitir)n  e)f  the 
windows  in  the  room.  Remember  that  air  without  direct  draft  i.s  what  im 
desired. 

Method.  —  Recall  the  experiment  of  the  candle  and  the  box  with 
the  holes  in  it.  (See  prol)lem  214.)  Wlial  hapjx'ned  when  the 
corks  were  removed  from  the  two  upper  holes  on  one  sid(»  only? 
The  two  lower  holes  on  one  side  only?  The  uj)p(*r  and  lower 
holes  on  one  side  only?  Now  apply  this  principle  to  the  room  in 
which  you  sleep.  Make  a  diagram  to  show  the  air  currents  in 
the  room  when  you  open  the  window  for  ventilation.  Is  this  the 
best  way  to  have  the  air  currents  move?     Why? 

Where  should  you  place  the  bed  and  why'.'  ShouM  yon  uso  a 
screen  in  your  room?     If  so,  where  should  you  place  it  ? 

Conclusion.  —  Make  a  diagram  showing  the  best  way  to  ventilate 
your  bedroom  and  give  your  reasons  for  tliinking  this  is  the  best 
way. 

Problem  2.3 r> :  To  C07nj)are  the  cJitster  and  the  dry  clotJi  witJi 
the  moist  cloth  in  cleaning  the  schoolroom . 

Materials.  —  Sterile  Petri  dish  with  culture  inciliuin.  broom, 
oiled  rags,  oiled  sawdust. 

Method.  —  Expose  a  sterile  Petri  dish  cultinc  in  \\\v  schoolroom 
for  two  minutes  while  members  of  the  class  tlust  with  dry  cU)tlis 
and  broom. 

The  same  day  have  members  of  the  class  clean  a  neighboring 
room,  having  the  same  conditions  of  dust  and  dirt.  l)y  means  of 
damp  cloths  and  brooms  witli  damp  cloths  tied  or  i)inned  over 
the  part  that  touches  the  surface  of  the  lloor.  Ise  damp  sawdust 
on  the  floor.     Expose  Petri  dish  as  in  above  test. 

Try  the  experiment  in  a  third  room,  using  oiled  rags  and  oiled 
sawdust.     Expose  Petri  dish  as  in  test  nunib(>r  one. 


264     MAN'S   IMPROVEMENT   OF   HIS   ENVIRONMENT 

Place  the  three  Petri  dishes  in  a  moderately  warm  and  dark 
place  for  three  days.     Then  examine. 

Observations.  —  In  which  of  the  three  dishes  are  the  most 
colonies  of  bacteria  and  molds?  Continue  your  observations  for 
about  one  week's  time. 

Conclusion.  —  Which  of  the  above  methods  of  dusting  a  room 
is  the  most  hygienic  and  why?  (Read  Hodge,  Nature  Study  and 
Life,  page  476.) 

Prohlein  236 :  What  should  I  eat  for  luncheon  ? 

Materials.  —  Food  tables  on  pages  204  to  209. 

Method  and  Observations.  —  Eight  boys  in  a  class  eat  the 
following  lunches : 

A  brings  from  home  two  ham  sandwiches,  a  sponge  cake,  and 
an  orange. 

B  brings  from  home  two  cheese  sandwiches  and  buys  a  glass  of 
milk  and  five  cents'  worth  of  candy. 

C  buys  a  hot  roast  beef  sandwich,  a  cup  of  cocoa,  and  an 
apple. 

D  buys  a  dish  of  ice  cream,  one  piece  of  sponge  cake,  and  five 
cents'  worth  of  candy. 

E  brings  two  slices  of  bread  and  a  square  of  chocolate  and  buys 
a  glass  of  milk. 

F  buys  a  Frankfurter,  a  roll,  a  small  helping  of  sauerkraut, 
and  a  glass  of  lemonade. 

G  buys  a  plate  of  vegetable  soup,  a  slice  of  bread  and  butter, 
a  cup  of  tea  with  milk  and  sugar,  and  a  piece  of  apple  pie. 

H  buys  a  helping  of  beans  and  a  dish  of  ice  cream. 

Using  the  tables  on  pages  204-209,  work  out  the  proportion  of 
carbohydrate,  fat,  and  protein  contained  in  each.  Add  up  the 
total  number  of  Calories  in  each.  Use  any  standard  you  wish, 
Atwater,  Chittenden,  or  Voit. 

In  like  manner  add  your  own  luncheon  to  the  list. 

Conclusion.  —  Which  do  you  think  the  best  balanced?  Which 
the  most  poorly  balanced?  Which  the  cheapest  (most  nutri- 
ment for  the  least  money)  ?  Which  the  best  for  a  spring  or  a  fall 
luncheon  ? 


PKOBLEM   237  oOo 

Problem  2:J7:  To  make  a  satiitarij  nia/j  of  m  1/  aivn  curinm- 
ment. 

Method  and  Observations.-  1 .  xMako  a  h\Y]n^  map  of  your 
immediate  neighborhood  by  diawinn;  to  scale  on  cardboard,  <.r 
heavy  paper,  a  map  of  your  home  block  (if  you  live  in  the  city) 
or  the  neighborhood  surrounding  your  liouse  (if  you  live  in  a  small 
town).  Locate  on  the  map  all  the  houses  by  oblong  shaded  areas 
and  use  cross  hnes  to  indicate  stores.  Make  an  index  at  the 
bottom  of  the  map  to  exphiin  the  uses  of  the  different  stores  or 
buildings  shown.  Using  board  of  health  signs,  indicate  any  homes 
in  which  your  local  board  of  health  has  placarded  contagious 
diseases. 

2.  Locate  on  the  map  any  standing  water,  especially  water 
in  old  tin  cans,  gutters,  or  depressed  roofs,  sewer  openings,  catch 
basins,  open  barrels,  or  small  ponds  in  vacant  lots,  ^^'hy  should 
you  locate  standing  water? 

3.  Find  the  position  of  any  stables  and  determine  if  the  heaps 
of  manure  are  allowed  to  collect  and  stand  for  long  periods  of 
time.  Why  would  such  manure  heaps  be  a  menace  to  the  public 
health  of  your  neighborhood  ? 

4.  Notice  the  condition  of  the  garbage  pails  in  your  neighl)or- 
hood.  Is  garbage  collected  regularly  ?  Are  all  the  pails  provided 
with  covers?  If  not,  locate  coverless  pails.  Does  garbage  ever 
stand  for  more  than  two  or  three  days  without  colhn'tion?  Are 
the  garbage  pails,  after  the  collection  of  garbage,  washed  clean, 
or  is  garbage  allowed  to  remain  sticking  to  the  sides  of  the  pails 
from  one  week  to  another?  What  dangers  might  arise  from  such 
pails  as  the  latter? 

5.  Investigate  the  condition  of  all  butcher  shops,  restaurants, 
or  stores  where  perishable  food  is  exposed  for  sale.  Do  you  lind 
the  shops  screened,  and  the  exposed  footl  j)rotected  from  flies? 
Are  there  excessive  numbers  of  flies  in  the  ])utcher  shops?  If  .so, 
then  try  to  locate  their  breeding  |ilaces.  Look  for  bits  of  stale 
meat  or  other  refuse  that  may  have  been  allowed  to  stand  un- 
touched in  a  given  place  for  over  two  weeks. 

6.  Locate  any  sewer  openings  or  catch  basins  from  which  come 
bad   odors.     Also   locate  any  outdoor   j)rivies,   especially   if  not 


266    MAN'S   IMPROVEMENT   OF   HIS   ENVIRONMENT 

connected  with  the  sewer  system  of  the  city.  If  such  toilets  are 
not  screened  from  flies,  report  the  matter  at  once  to  your  board  of 
health.  Why  are  the  latter  toilets  a  particular  menace  to  public 
health?     (See  Civic  Biology,  page  224.) 

7.  Locate  on  your  map  any  pushcarts,  stands,  or  stores  in  which 
vegetables  or  fruit  are  exposed  for  sale.  Indicate  if  they  are 
obeying  the  laws  of  your  sanitary  code  with  reference  to  the  ex- 
posure of  goods  for  sale.  Why  is  it  a  wise  law  that  requires  goods 
exposed  for  sale  to  be  covered  ?  Is  there  any  spitting  in  the  streets 
in  this  locality?  Are  there  any  other  ways  in  which  germs  might 
get  in  the  dust  of  the  street?  How  might  bacteria  be  carried 
from  the  street  surface  to  the  food  exposed? 

8.  Find  any  public  fountains  having  drinking  cups ;  bubble 
fountains.     Which  is  more  hygienic?     Why? 

9.  Locate  any  hotels  or  other  places  having  common  roller 
towels.  Why  are  common  towels  a  danger  to  public  health? 
What  can  you  do  to  prevent  the  use  of  the  public  towel  in  your 
neighborhood  ? 

10.  Locate  any  other  factors  that  might  in  your  opinion  affect 
public  health  in  your  neighborhood.  Factories  belching  forth 
smoke  or  acid  fumes,  tall  buildings  shutting  out  light,  old  tenement 
houses,  and  filthy  conditions  of  street  are  among  such  factors. 

Conclusion.  —  L  Is  my  neighborhood  a  good  one  in  which  to 
live?     Give  reasons. 

2.  How  may  I  help  to  better  the  conditions  that  affect  public 
health  in  my  locality? 

Problem  238 :  To  determine  the  hacterial  content  of  different 
grades  of  milh. 

Materials.  —  Different  grades  of  milk,  sterile  bulb  pipette, 
sterile  test  tubes,  absorbent  cotton,  sterile  Petri  dishes  containing 
agar  culture  media. 

Method.  —  Procure  milk  from  different  sources  and  of  different 
grades  if  in  a  large  city.  Be  sure  to  include  milk  dipped  from  a 
can  in  some  store.  Have  samples  of  milk  collected  kept  under 
identical  conditions  and  be  sure  that  the  milk  has  been  collected 
from  the  milk  companies  at  the  same  time.     Then  treat  each 


PROBLEM   2;ilj 


207 


sample  according  to  the  following  directions:  Willi  a  .sterile 
bulb  pipette  draw  off  1  c.c.  of  milk  from  a  ucU-shaken  sample 
bottle.  Add  to  this  19  c.c.  of  distilled  water,  taking  care  to  have 
the  water  in  a  sterile  test  tube,  protected  from  any  dust  by  an 
absorbent  cotton  plug.  After  mixing  the  contents  of  the  tulx; 
thoroughly,  quickly  flood  the  surface  of  a  sterile  Petri  (hsh  con- 
taining agar  culture  media  with  the  mixture  of  milk  and  water. 
Drain  the  dish,  keeping  it  covered  durin«^  the  operation;  hibel ; 
fasten  down  the  cover  with  strips  of  paper ;  and  j)lace  to  one 
side.  Treat  each  of  the  other  samples  of  milk  in  the  same 
manner  as  just  described,  taking  care  to  lalx'l  each  as  to  the 
source  of  the  milk,  etc.  Place  the  dishes  side  by  side  in  a  mod- 
erately warm  place. 

Observations.  —  After  two  days,  and  on  each  successive  day  for 
a  week,  examine  the  different  Petri  dishes.  Count  the  number  of 
colonies  in  each  dish. 
Also  note  the  different 
kinds  of  colonies  of 
bacteria  present  in 
each  of  the  Petri 
dishes.  Tabulate  the 
results. 

Conclusion.  —   1. 
Which  of  the  grades  of  milk  examined  sooms  to  be  most  free  from 
bacteria  ? 

2.  Should  milk  be  entirely  free  from  l)a('teria?  W  hat  do  the 
bacteria  present  in  greatest  quantities  probably  do  to  tiie  nulk? 

3.  If  several  kinds  of  bacteria  are  present  in  milk,  what  can  you 
say  of  its  purity?  What  ought  to  be  done  with  such  milk  l)efore 
it  is  used? 


Milk 

3D 

4D 

5D 

Ki  «\ei8  in. 

A. 

B 

C 

D 

E 

F 

Problem  ?.?»:   To  detrrniinr   tlir  bartrrial  ronfnif  of  soms 
kinds  of  water. 

Materials.  —  See    Problem    238.     nmit     milk    and    substitute 

samples  of  water. 

Method. —  By  means  of  a  sterile  l)ull)  i)ipette  place,  m  sterile 
Petri    dishes   containing   agar  culture    media.    v(\\\i\\   amounts  of 


268     MAX'S   IMPROVEMENT  OF   HIS   ENVIRONMENT 

different  waters  to  be  tested.  Suggested  samples  are  as  follows : 
distilled  water,  rain  water,  bottled  spring  waters  of  various  kinds, 
city  tap  water,  standing  water  from  lakes  or  pools  near  your  home, 
river  water  thought  to  contain  sewage,  dilute  sewage.  After 
inoculating  the  Petri  dishes  with  the  water  to  be  tested,  place  all 
Nxn^bei-o/ Colonies  i>v  e«cK  of  the  dlshes  Contain- 
ing the  samples  in  a 
moderately  warm  place. 
Examine  after  two  or 
three  days,  and  on  suc- 
cessive days  for  one 
week.  Tabulate  the 
results. 

Observations.  —  In  which  Petri  dishes  does  the  most  bacterial 
growth  take  place? 

Conclusion.  —  1.   Which  of  the  examined  samples  of  water  are 
free  from  bacteria? 

2.  Which  of  the  samples  are  best  for  drinking  purposes?     Give 
reasons  for  your  answer. 


\A,^citer 

3D 

4I> 

5D 

A. 

B 

C 

D 

K 

F 

Problem  240 :  To  determine  some  of  the  problems  of  water 
supply  and  sewage  disposal  for  a  city. 

Method.  —  Visit  the  sanitation  exhibit  in  a  city  museum. 

Observations.  —  From  information  gained  from  maps  in  the 
museum,  or  in  some  other  way,  trace  the  growth  of  the  water 
supply  of  your  city  since  its  beginning.  Where  did  the  city  first 
get  its  water?     What  is  now  the  source  of  the  water  supply? 

What  impurities  are  commonly  found  in  water?  What  do 
reservoirs  do  to  a  water  supply  ?  State  several  ways  in  which  a 
water  supply  becomes  contaminated.  How  might  contaminated 
waters  bounding  a  city  affect  the  health  of  the  citizens  of  that 
city? 

How  does  the  sewage  of  your  city  affect  the  waters  surrounding 
it?  How  is  this  contamination  brought  about?  What  methods 
are  there  for  sewage  disposal  ?  Which  would  you  choose  for  use  in 
your  city?     Why?     How  is  sewage  now  disposed  of? 

How  do  conditions  of  water  supply  and  sewage  disposal  on  a 


PK01iLi:M   212 


2<;9 


farm  compare  with   those  in  a  city?     How  <aii   tlic  unsanitary 
environment  of  the  farm  be  made  sanitary? 

Conclusion.  —  1.  What  steps  should  a  lar^e  city  take  to  obtain 
and  protect  its  water  supply? 

2.  What  should  be  done  with  the  sewage  in  the  city  in  which 
you  live?     Why? 

3.  What  other  hygienic  steps  should  a  city  take  to  protect  its 
citizens  ? 

Problem  241 :  Is  typhoid  a  city  or  a  country  diseasr  ? 

Observation.  —  Make  a  graph  from  the  following  table  '  to  show 
the  relative  death  rate  from  typhoid  in  states  ha\ing  a  large 
urban  population,  and  in  states  having  a  large  rural  population. 


Five  states  in  which  the  city  population 

was  more  than  60  %  of  the  total       .     . 
Six  states  in  which  the  city  population 

was  between  40  %  and  60  %    .     .     .     . 
Seven  states  in  which  the  city  population 

was  between  30  %  and  40  %    . 
Eight  states  in  which  the  city  population 

was  between  20  %  and  30  %    .     .     .     . 
Twelve  states  in  which  the  city  population 

was  between  10  %  and  20  %    .     .     .     . 
Twelve  states  or  territories  in  which  the 

city  population  was  less  than  10  '  j    • 


AvKRAGK  Pkr      I  AvERAur  Ttphoid 
Cknt  ok  Rukal    '      f^»-^»"  f^»-^T" 


Population 

IVATK    PKK 
100.000 

30 

25 

49 

42 

67 

38 

75 

46 

ST 

62 

9.", 

67 

Conclusion.  —  Is  typhoid  a  city  or  a  country  diseiu^e?  Why 
is  it  so?     Look  up  diagram  in  your  textl)ook. 

Problem  242  :  What  is  the  (Uinuai  cost  to  .Xew  Ym  k  city  af 
some  ])r event cible  diseases  ? 

Materials.  —  Report  of  board  of  health. 

Method.  —  Using  the  board  of  healtli  tal)les  for  the  year  1910, 
find  the  number  of  persons  who  die  from  each  of  the  given  prevent- 
able diseases.  Which  are  particularlx  children's  diseases?  Fol- 
lowing these  directions,  compute  the  annual  cost  in  lives. 

'  Modified  from  Ailen'a  Cincs  and  Htalth. 


270    MAN'S   IMPROVEMENT  OF   HIS  ENVIRONMENT 


City  of 

City  of 

City  of 

City  of 

City  of 

City  of 

New  York 

New  York 

New  York 

New  York 

New  York 

New  York 

Jan. 

Jan. 

Feb.    Feb. 

Mar.'  Mar, 

Apr. 

Apr. 

May   May 

June  June 

1911 

1910 

1911    1910 

1911    1910 

1 

1911 

1910 

1911    1910 

1911 

1910 

Total  deaths,  all  causes 

6,961 

7.090 

6,470 

6,270 

7.445 

7.300 

7,185 

6,916 

6,677 

6,323 

5,368 

5,946 

Typhoid  Fever      .     . 

27 

37 

21 

27 

24 

32 

20 

24 

24 

23 

32 

37 

.^iala^ial  Fever      .     . 

1 

1 

.    .    . 

3 

6 

1 

1 

3 

9 

1 

1 

Smallpox      .... 

.    .    . 

2 

1 

2 

Measles        .... 

34 

"77 

'57 

'77 

"72 

i29 

'77 

135 

li6 

107 

113 

85 

Scarlet  Fever   .     .     . 

65 

150 

85 

150 

126 

159 

143 

148 

131 

116 

73 

83 

Whooping  Cough 

29 

17 

31 

13 

31 

17 

37 

29 

40 

28 

35 

25 

Diphtheria  and  Croup 

135 

202 

128 

183 

149 

212 

151 

221 

161 

186 

90 

152 

Influenza      .... 

152 

47 

101 

49 

82 

75 

50 

52 

35 

24 

6 

13 

Asiatic  Cholera     .     . 

.    .    . 

Cholera  Nostras    .     . 

.    .    . 

.    .    . 

,    ,   , 

•    •    . 

•    •   • 

Other  Epidemic  Dis- 

eases      

47 

42 

52 

53 

53 

61 

68 

35 

71 

41 

51 

38 

Tuberculosis,  Pulm   . 

814 

767 

782 

707 

824 

859 

835 

809 

812 

755 

678 

657 

Tub.,  Meningitis  .     . 

67 

76 

71 

69 

84 

67 

81 

64 

103 

88 

95 

79 

Other  Forms  of  Tuber- 

culosis      .... 

46 

48 

54 

42 

53 

56 

51 

64 

61 

53 

51 

43 

Cancer,         Malignant 

Tumor      .... 

309 

298 

275 

301 

319 

330 

302 

301 

323 

311 

292 

304 

Simple  Meningitis 

53 

51 

49 

52 

75 

62 

44 

52 

51 

58 

48 

51 

Of  which 

Cerebro-Spinal     Men- 

ingitis      .... 

22 

26 

27 

23 

25 

26 

18 

30 

19 

30 

15 

27 

Apoplexy,  and  Soften- 

ing of  Brain .     .     . 

134 

102 

94 

83 

80 

94 

105 

66 

63 

98 

62 

74 

Organic    Heart   Dis- 

eases     

831 

679 

719 

629 

738 

603 

721 

576 

684 

573 

528 

557 

Acute  Bronchitis 

98 

125 

95 

92 

94 

96 

97 

95 

77 

57 

44 

65 

Chronic  Bronchitis    . 

41 

48 

44 

39 

29 

37 

28 

58 

26 

37 

25 

17 

Pneumonia  (exc.  Bron- 

cho Pneumonia)     . 

753 

708 

632 

527 

736 

736 

725 

646 

456 

470 

253 

307 

Broncho    Pneumonia 

486 

624 

486 

515 

640 

597 

590 

538 

484 

408 

298 

334 

Other        Respiratory 

Diseases  .... 

77 

84 

65 

59 

87 

87 

80 

96 

86 

74 

48 

63 

Diseases        of        the 

Stomach      (Cancer 

excepted)       .     .     . 

45 

40 

43 

45 

39 

54 

35 

41 

37 

46 

39 

32 

Diarrheal       Diseases 

(under  5  years) 

154 

150 

186 

129 

274 

162 

243 

210 

264 

248 

272 

463 

Appendicitis           and 

Typhlitis       .     .     . 

48 

54 

48 

48 

44 

57 

61 

56 

53 

43 

54 

56 

Hernia,  Intestinal  Ob- 

struction       .     . 

54 

46 

56 

48 

46 

56 

37 

44 

48 

39 

40 

50 

Cirrhosis  of  Liver 

102 

128 

91 

99 

127 

89 

96 

91 

101 

86 

93 

93 

Bright's  Disease  and 

Nephritis       .      .      . 

551 

529 

485 

498 

558 

549 

535 

498 

454 

483 

342 

460 

Diseases    of    Women 

(not  Cancer)      .     . 

26 

25 

21 

29 

37 

23 

36 

36 

36 

41 

42 

33 

Puerperal  Septicaemia 

28 

29 

25 

31 

27 

36 

26 

33 

31 

20 

24 

24 

Other  Puerperal  Dis- 

eases     

40 

43- 

38 

46 

45 

52 

38 

46 

47 

47 

43 

43 

Congenital     Debility 

and  Malformations 

354 

392 

342 

329 

357 

432 

323 

366 

282 

402 

271 

348 

Old  Age        .... 

71 

68 

44 

60 

64 

65 

54 

48 

48 

74 

24 

60 

Violent  Deaths      .     . 

274 

326 

261 

222 

417 

281 

302 

299 

361 

313 

324 

323 

a.    Sunstroke     .     . 

6 

25 

b.    Other  Accidents 

249 

296 

248 

203 

395 

262 

284 

276 

337 

293 

298 

273 

c.    Homicide      .     . 

25 

30 

13 

19 

22 

19 

18 

23 

24 

20 

20 

25 

Suicide 

62 

69 

50 

59 

64 

66 

75 

65 

74 

79 

69 

92 

All  Other  Causes  .     . 

924 

973 

913 

916 

1015 

1022 

1089 

1030 

1005 

848 

879 

815 

Ill-defined  Causes 

29 

35 

26 

41 

29 

46 

29 

39 

23 

45 

30 

67 

PR0BL1:M   212 


271 


City  of 

City  of 

City  of 

'     City  of 

City  of 

1 

Lit 

>•  of 

New  York 

New  York 

New  York 

New  York 

New  York 

New 

York 

July 

July 

Aug. 

Auk. 

Sept.'Sopt. 

Ort. 

Ort. 

\ov. 

N'ov. 

!).•< 

I  >«•<•. 

1911 
6,648 

1910 
7,060 

1911 

1910 

1911    1910 

1 

1911 

I'.dO 

78 

I'tn 
67 

l'»lf) 
66 

1911 
52 

191U 

Total  deaths,  all  causes 

6,039 

6,052 

5.361 

5,671 
71 

■    ! '  t  " 

63 

f  ■::■ 

Typhoid  Fever 

56 

53 

88 

58 

81 

62 

Malarial  Fever 

2 

3 

2 

5 

5 

3 

7 

3 

3 

2 

2 

1 

Smallpox      .... 

1 

2 

Measles        .... 

'76 

60 

ii 

38 

is 

28 

n 

".» 

if) 

19 

33 

21 

Scarlet  Fever    .     .     . 

40 

39 

11 

11 

11 

16 

7 

12 

i.'j 

24 

34 

45 

Whooping  Cougli 

46 

46 

49 

41 

35 

21 

30 

17 

8 

1     18 

15 

22 

Diphtheria  and  Croup 

80 

116 

76 

92 

49 

55 

78 

1     76 

84 

112 

100 

108 

Influenza      .... 

2 

5 

1 

3 

5 

1 

10 

7 

16 

14 

21 

76 

Asiatic  Cholera     . 

Cholera  Nostras    . 

46 

36 

32 

25 

24 

27 

Other  Epidemic  Dis- 

eases      

35 

39 

43 

44 

658 

674 

658 

666 

673 

662 

24 

26 

Tuberculosis,  Pulm   . 

650 

728 

693 

665 

711 

743 

Tub.,  Meningitis  . 

82 

77 

67 

54 

58 

61 

'60 

'58 

49 

55 

46 

53 

Other  Forms  of  Tuber- 

culosis      .... 

50 

57 

55 

48 

38 

48 

32 

43 

42 

37 

64 

42 

Cancer,       ^Malignant 

Tumor      .... 

315 

291 

345 

316 

328 

319 

376 

323 

337 

308 

337 

308 

Simple  Meningitis 

35 

52 

53 

41 

36 

45 

39 

48 

31 

1     36 

28 

60 

Of  which 

Cerebro-Spinal   Men- 

ingitis      .... 

18 

23 

22 

19 

19 

21 

14 

25 

13 

15 

9 

29 

Apoplexy,  and  Soften- 

ing of  Brain       .     . 

105 

66 

54 

44 

62 

74 

63 

89 

75 

87 

108 

102 

Organic    Heart    Dis- 

eases     

596 

460 

525 

391 

529 

463 

629 

503 

706 

6as 

768 

S28 

Acute  Bronchitis 

40 

45 

32 

48 

36 

60 

59 

52 

87 

84 

115 

109 

Chronic  Bronchitis    . 

8 

27 

15 

11 

14 

14 

15 

18 

22 

35 

27 

66 

Pneumonia  (exc.  Bron- 

cho Pneumonia)     . 

215 

199 

152 

176 

165 

197 

280 

309 

365 

430 

543 

835 

Broncho    Pneumonia 

251 

286 

245 

241 

238 

288 

288 

287 

348 

332 

429 

529 

Other        Respiratory 

Diseases 

60 

55 

42 

47 

30 

64 

48 

41 

55 

65 

58 

85 

Diseases        of        the 

Stomach      (Cancer 

excepted)       .     .     . 

41 

25 

35 

41 

38 

40 

45 

51 

38 

35 

37 

61 

Diarrheal       Diseases 

(under  5  years) 

807 

1632 

1034 

1175 

701 

791 

408 

572 

174 

231 

168 

165 

Appendicitis          and 

Typhlitis.     .     .     . 

77 

80 

69 

58 

55 

39 

31 

59 

41 

36 

60 

58 

Hernia,  Intestinal  Ob- 

struction       .     .     . 

47 

53 

46 

58 

41 

46 

31 

43 

52 

41 

45 

60 

Cirrhosis  of  Liver 

73 

74 

93 

102 

95 

100 

102 

76 

114 

so 

KM) 

122 

Bright's  Disease  and 

Nephritis       .     .     . 

379 

414 

335 

412 

326 

380 

363 

388 

410 

469 

449 

558 

Diseases    of    Women 

(not  Cancer)      .     . 

32 

35 

24 

24 

11 

22 

32 

28 

29 

28 

11 

27 

Puerperal  Septicaemia 

17 

11 

25 

20 

20 

13 

10 

9 

17  ! 

13  1 

20  ! 

16 

Other  Puerperal  Dis- 

1 

eases    

36 

49 

43 

36 

32 

37 

34 

34 

36 

32 

i.'i 

M 

Congenital     Debility 

I 

1 

and  Malformations 

314 

319 

332 

360 

313 

351 

318 

370 

316  ! 

292 

an?  1 

:<90 

Old  Age        .... 

51 

46 

24 

50 

28 

39 

40       32 

29 

(\:\ 

Violent  Deaths      ,     . 

939 

534 

361 

331 

323 

284 

293 

308 

300 

aio 

a.    Sunstroke     .     . 

535 

11.-) 

17 

12 

1 

9 

•    •    . 

.   •  * 

•    •   . 

b  .  Other  Accidents 

379 

389 

322 

28(5 

301 

253 

268 

290 

270 

28- 

_  "■    i 

2rv:< 

c.    Homicide      .     . 

25 

30 

22 

33 

21 

22 

25 

is 

.;i  1 

19 

M 

19 

Suicide 

57 

85 

50 

59 

43 

67 

63 

64 

.'.s 

M 

72 

57 

All  Other  Causes  .     . 

941 

886 

883 

836 

804 

838 

844 

807 

961 

971 

921 

«m;« 

Ill-defined  Causes 

93  1 

1 

113 

96 

116 

89 

89 

»5, 

72 

37  , 

24 

s 

21 

272    MAN'S   IMPROVEMENT  OF  HIS   ENVIRONMENT 

Conclusion.  —  What  is  the  annual  cost  of  typhoid,  tuberculosis, 
and  diarrheal  diseases  of  children  to  the  city  of  New  York  ? 

Problem  243 :  What  are  the  chief  causes  of  death  in  a  city  ? 
Method  and  Observations.  —  From  the  foregoing  table  deter- 
mine : 

(1)  The  relation  of  the  number  of  deaths  from  infectious  dis- 
eases to  the  total  death  rate. 

(2)  The  diseases  which  kill  the  most  children. 

(3)  The  per  cent  who  actually  die  of  old  age. 

Conclusion.  —  1.  What  percentage  of  all  people  of  the  city  die 
from  old  age? 

2.  What  diseases  kill  most  babies  and  children  under  five  years 
of  age  ? 

3.  What  diseases  in  the  list  might  be  influenced  by  alcohol? 

Problem  244 :  To  study  the  relation  of  the  death  rate  to  the 
season. 

Method.  —  Study  tables  carefully  in  the  following  manner : 
Note  a  given  disease,  as  typhoid,  and  make  a  graph,  using  figures 
given,  to  determine  the  number  of  cases  reported  and  number  of 
deaths  monthly  in  New  York  city. 

Conclusion.  —  Is  typhoid  equally  prevalent  all  the  year  round  ? 
How  do  you  account  for  its  great  prevalence  in  the  fall? 

(The  instructor  should  divide  up  the  work  so  that  each  member 
of  the  class  will  be  responsible  for  a  separate  graph.  A  general 
discussion  may  then  be  held  on  the  relation  of  various  diseases 
to  the  city  death  rate.  For  example  :  What  disease  is  responsible 
for  the  greatest  death  rate  ?) 

Problem  245 :  To  find  a  relation  between  flies  and  mortality. 

Method.  — Refer  to  mortality  tables  published  on  pages  270, 
271,  and  fill  in  the  table  on  the  opposite  page. 

Observations.  —  With  the  aid  of  the  given  data,  construct  a 
graph  showing  the  prevalence  of  flies  and  number  of  deaths  per 
month  for  the  dates  given.  (In  making  curves  on  cross  section 
paper  let  1  cm.  =  50  deaths,  and  1  cm.  =  200  flies.) 

Conclusion.  —  1.  Is  there  any  relation  between  the  prevalence 
of  flies  and  the  number  of  deaths  from  diarrhea? 


PROBLEM   210 


273 


Date 

Jan. 

Feb. 

March 

April 

May 
0 

June 
250 

Jdlt 

1900 

Aug. 
2200 

Sept. 
200 

Oct. 

Nov. 

Dtc. 

Diarrheals    under 
five      .... 

0 

0 

Average       .     .     . 
Prevalence  of  flies 

0 

0 

40U 

U 
1 

1" 

2.  What  factors  increase  the  death  of  babies  during  the  .sunmicr 
months  ? 

3.  How  would  you  fight  these  unfavorable  factors? 

Problem  246 :  To  determine  the  numhrr  of  srliool  cJtihlmi 
who  needed  treatment  for  different  diseases  in  .Vew  York  city, 
1914-1915. 

Method.  —  Examine  the  following  table  carefully.  Estimate 
the  percentage  of  pupils  needing  attention;  the  nuinl^er  having 
defective  teeth,  vision,  hearing,  and  enlarged  tonsils. 

Conclusion.  —  1.  Would  any  of  the  difficulties  stated  in  tlio  table 
interfere  with  studies?     Name  and  give  reason. 

2.  How  would  you  improve  scholarship  conditions  in  the  New 
York  city  schools  ? 

Physical  Examination  of  School  Children,  1014-1915,  in  New 

York  City 


Total 


Number  of  children  examined     .     . 
Defects  found : 

Malnutrition 

Heart  troubles 

Pulmonary  disease 

Defective  vision 

Defective  hearing 

Obstructed  nasal  breathing     .     . 

Defective  teeth 

Enlarged  tonsils 

Orthopedic  defects 

Nervous  diseases 

General  defects 

hunter  lab.  prob.  —  18 


:i()5.(")l)5 

1().;m() 

4.121 
5()'J 

25,5:n 

l.STO 

'J«>.()r.7 

11  ).").:>!>:) 

:vi.:i7s 

1.7J«> 

1  .s,s7 

S().«')()7 


Percentaqe 


KM) 


274    MAN'S   IMPROVEMEKT  OF  HIS  ENVIRONMENT 

Prohletn  247 :  How  to  discover  tlie  presence  of  adenoids. 

Method.  —  A  good  medical  authority  has  given  the  following 
symptoms  as  indicating  the  presence  of  adenoids,  growths  in  the 
nose  and  throat  which  prevent  a  sufficient  air  supply  from  reaching 
the  tissues  of  the  body  : 

1.  Inability  to  breathe  through  the  nose. 

2.  A  chronically  running  nose,  accompanied  by  frequent  nose- 
bleeds and  a  cough  to  clear  the  throat. 

3.  Stuffy  speech  and  delayed  learning  to  talk.  '  Common  '  is 
pronounced  '  cobbed  ' ;  '  nose/  '  doze  ' ;  and  '  song/  '  sogg.' 

4.  A  narrow  upper  jaw  and  irregular  crowding  of  the  teeth. 

5.  Deafness. 

6.  Nervousness. 

7.  Inflamed  eyes. 

Observations.  —  Observe  members  of  your  own  family. 
Conclusion.  —  1.    Do  any  of  the  family  appear  to  have  adenoids  ? 
What  makes  you  believe  this? 

2.   What  ought  people  suffering  with  adenoids  to  do? 

Problem  248 :  To  find  some  ways  of  preventing  the  spread  of 
disease. 

Note.  —  Remembering  that  disease  germs  must  come  from  the  bodies  of  those 
who  are  sick  and  that  such  germs  are  spread  usually  by  means  of  material  from  the 
mouth,  food  tube,  or  other  openings  where  germs  could  escape,  our  problem  be- 
comes threefold.  The  three  parts  of  the  main  problem  are  :  first,  the  destruction  of 
such  germs  as  escape  from  the  bodies  of  the  sick ;  second,  the  prevention  of  such 
germs  as  escape  from  entering  the  body  of  well  people ;  and  third,  the  problem  of 
how  to  make  the  body  safe  or  immune  from  the  attacks  of  such  germs  as  do  get  into 
the  body  of  a  well  person. 

a.  How  to  kill  Germs  that  escape  from  the  Bodies  of  those  who 

are  Sick 

Method  and  Observations.  —  Using  your  Civic  Biology  and  such 
other  books  of  reference  as  you  have  access  to,  answer  the  follow- 
ing questions: 

Take  some  specific  disease,  as  typhoid  fever,  tuberculosis,  or 
diphtheria.  From  what  part  of  the  body  do  the  disease-causing 
germs  escape  ? 


PR()BLI':M   248  275 

Having  dotenniiKHl  (his  point,  ik-m  apply  what  you  have 
learned  about  disinfectants  to  the  particuhii-  (hs(  asr  you  are  trying; 
to  prevent  the  spread  of  from  one  person  to  another.  i{cnienilx?r 
contact  with  the  germ  is  necessary  in  order  for  the  well  ixjrson  to 
take  the  disease. 

In  the  case  of  tuberculosis  what  methods  would  you  advocate 
for  receiving  and  destroying  the  material  from  the  mouth  (sputum) 
containing  the  disease  germs? 

Conclusion.  —  How  would  you  destroy  the  disea.se  germs  in  a 
given  disease  such  as  tuberculosis,  typhoid,  or  diphtheria? 

b.  How  to  prevent  the  Germs  of  those  Sick  from  Reaching  those  in 
Neighboring  Families  who  are  Well.     Quarantine 

Method  and  Observations.  — Notice  the  manner  in  which  your 
local  board  of  health  treats  families  in  which  infectious  disea,se 
has  come. 

Note.  —  This  isolation  of  the  patient  is  called  quarantine.  Quarantine  may  l)c 
done  in  the  home  or  by  removing  the  sick  jxTson  to  a  hospital  wlnrf  only  that 
particular  disease  is  treated. 

Why  should  persons  ill  with  a  germ  disea.se  be  i.solated  until 
they  are  well?  What  methods  have  the  board  of  healtli  for  warn- 
ing strangers  of  the  presence  of  the  disease  in  a  home?  Why  is 
this  necessary?  What  should  be  done  with  heavy  rugs,  curtains, 
etc.  in  the  room  where  one  is  ill  with  a  germ  disease?  Why? 
How  could  the  germs  that  might  lodge  in  such  hangings  be  kilhMl"' 
Suggest  methods.  What  do  we  mean  by  disinfection'.'  Look  up 
your  local  board  of  health  rules  on  disinfection  and  note  what  is 
used  and  how  used.  (See  page  390,  Civic  Biology.)  Wliat  should 
be  done  to  the  body,  clothing,  and  hair  of  a  person  who  has  Ikhmi 
ill  with  a  germ  disease  before  he  is  allowed  to  go  among  well 
persons  again  ?  Why  is  this  necessary?  Would  a  person  lu 
selfish  who  neglected  such  precautions?     (^dve  reasons. 

Conclusion.  —  1.  What  is  the  reason  for  cjuarantine  and  l>v 
what  should  it  be  followed  to  be  effective  ? 

2.  Why  is  there  a  quarantine  station  at  the  entrance  of  New 
York  harbor?     Why  is  it  of  particular  value  there? 


276     MAN^S   IMPROVEMENT   OF   HIS   ENVIRONMENT 

c.  How  to  keep  Germs  from  Entering  the  Body  of  a  Well  Person 

Method  and  Observations.  —  Notice  conditions  existing  in 
crowded  cities  with  reference  to  the  number  of  flies  and  the  relative 
number  of  screens  over  food  exposed  for  sale,  etc.  Note  the  con- 
dition of  the  streets  and  sidewalks,  locate  saloons  or  other  places 
where  spittoons  are  found.  Find  any  other  places  where  you  think 
germs  might  exist  and  from  which  they  might  be  carried  by  flies 
or  other  insects.  What  household  insects  might  be  disease 
carriers  ?     (See  Civic  Biology,  pages  225-227.) 

Do  you  find  any  public  drinking  fountains?  Any  common 
towels?     Common  combs  and  brushes? 

Also  inquire  into  the  condition  of  your  local  water  supply.  Is 
it  pure  at  the  source?  Does  the  supply  come  from  a  river?  If 
so,  are  there  any  towns  or  hamlets  that  empty  their  sewage  into  it  ? 
What  danger  might  come  from  this  ?  Is  your  city  doing  anything 
to  eUminate  this  danger  ?  What  might  your  city  do  to  prevent 
it  ?     What  can  you  do  to  prevent  disease  from  this  source  ? 

What  is  the  condition  of  your  milk  supply  ?  Does  your  board  of 
health  do  anything  to  protect  the  milk  supply  ?  If  so,  then  what 
does  it  do?  Are  several  grades  of  milk  sold?  Is  dipped  milk 
sold  ?     If  so,  for  what  purposes  ?     How  can  you  protect  yourself  ? 

What  is  the  condition  of  the  disposal  of  sewage  in  your  city? 
Does  the  sewage  reach  a  river  near  by  untreated,  or  is  the  sewage 
treated  before  it  escapes?  Look  up  some  book  of  reference  in 
this  chapter  on  sewage  disposal,  and  make  a  report  to  the  class 
on  some  of  the  methods  of  sewage  disposal.  Visit  a  municipal 
museum,  if  possible,  and  report  on  various  methods  of  sewage 
disposal  as  shown  in  the  sanitation  exhibit  there. 

Conclusion.  —  Write  up  a  short  composition  for  your  notebook, 
showing  afl  the  public  and  private  means  that  should  be  taken  to 
prevent  germs  from  entering  the  body  of  a  well  person. 

d.  How  to  develop  Immunity  in  the  Body  of  a  Well  Person 

Method  and  Observations.  —  Read  in  your  Civic  Biology  and 
other  reference  books  as  to  what  immunity  is  and  how  it  is  brought 
about. 


PR()IMJ:M   219  277 

Note.  —  immunity  is  usually  meant  when  the  Ixwiy  (irvdfjps  certain  HubHtfincca 
in  the  blood  known  as  antibodies.  These  substanceM  seem  to  give  to  the  Inxly  the 
power  to  r(>sist  the  work  of  genns  that  entir  it.  Natural  immunity  is  only  po»»il)lf 
when  the  bodily  condition  is  good. 

Of  what  use  to  the  body  in  this  respect  would  Ix'  {.^ood  food,  rest, 
sleep,  and  moderate  exercise?  Take  each  factor  separately  in  your 
discussion. 

What  might  the  colorless  corpuscles  do  to  help  in  tliis  gaining  of 
immunity  ? 

Note.  —  Artificial  immunity  to  certain  disea.ses  is  brousht  alxjut  in  the  lx>dy  l)y 
the  introduction  of  antitoxins  into  the  body.  These  s<ibstanees  finht  the  efTei-t**  of 
the  toxins  formed  in  the  body  by  the  Ixicteria  of  certain  disea.'<es.  Diphtheria  i.s 
one  disease  so  fought.  See  your  local  board  of  health  re|>orfs  for  u  statement  of 
the  preparation  and  distribution  of  this  antitoxin. 

Do  you  know  of  any  diseases  that  are  fought  succe.«^sfully  by 
antitoxins?  (Read  Civic  Biology,  pages  300-303.)  What  great 
names  are  connected  with  the  antitoxin  treat ukmU  of  disease? 
(See  Civic  Biology,  pages  391,  402,  etc.)  How  are  antitoxins  ad- 
ministered? Why  in  this  manner?  Look  uj)  tlic  .subject  of 
vaccination  in  Civic  Biology,  pages  157  and  301.  Who  discovered 
this  method  of  treatment  of  disease?  To  wliat  disea.ses  is  it 
applied?  Are  there  any  other  artificial  means  of  developing 
immunity  in  the  human  body  ? 

Conclusion.  —  Write  a  short  composition  discussing  all  the 
ways  of  developing  immunity  in  the  human  body. 

General  Conclusion.  —  1.  What  are  the  functions  of  the 
board  of  health  in  any  city? 

2.  How  may  I  cooperate  with  them  in  their  work  for  the  com- 
mon welfare? 

3.  How  may  I  develop  immunity? 

Problem  249  :  First  aid  in.  tJie  Iwmr.  ,4  siutimary  nf  ivluit 
to  do  and  how  to  do  it. 

Thf:  FiHftT-Aii)  1:mi:iigency  Mkdicink  Chkst 

Every  family  should  iia\f  the  following  materials  in  fix-  medieino 
cabinet  out  of  rcdcli  of  young  children  : 
Alcohol,  small  bottle. 


278     MAN'S   IMPROVEMENT   OF   HIS   ENVIRONMENT 

Aromatic  spirits  of  ammonia,  rubber  stoppered,  small  bottle. 

Carbolated  vaseline,  small  bottle. 

Castor  oil,  large  bottle. 

Boracic  acid,  one  ounce. 

Collodion,  in  bottle  with  small  brush  (use  for  small  cuts). 

Chlorate  of  potash  tablets. 

Mustard,  powdered,  two  ounces. 

Oil  of  cloves,  small  bottle  (label  poison). 

Seidlitz  powders,  small  box. 

Soda  mint  tablets,  small  bottle. 

Spirits  of  camphor,  small  bottle. 

Sirup  of  ginger,  small  bottle. 

Sirup  of  ipecac,  small  bottle. 

Subnitrate  of  bismuth,  five-grain  tablets,  small  bottle. 

Tincture  of  iodine,  small  bottle. 

The  following  articles  should  also  be  kept,  either  in  the  case  or  in 
an  emergency  kit : 

Adhesive  tape,  small  roll. 

Absorbent  cotton,  small  package. 

Antiseptic  gauze,  small  package. 

Clinical  thermometer. 

Bottle  of  peroxide  or  4  per  cent  carbolic  solution. 

Knife,  sharp  and  used  for  this  purpose  only. 

Scissors. 

Paper  of  pins,  safety  and  common. 

Tooth  plasters,  small  package. 

The  above-mentioned  articles  ought  to  be  sufficient  to  make 
unnecessary  the  presence  of  a  doctor  except  in  serious  cases  of 
illness. 

How  to  use  the  Materials  in  the  Medicine  Chest 

Method.  —  Use. any  good  pamphlets  or  books  on  first  aid.  The 
small  pamphlet  known  as  First  Aid  in  the  Home,  printed  and  dis- 
tributed free  of  charge  by  the  Metropolitan  Life  Insurance  Com- 
pany, may  be  used  as  a  text.  The  uses  of  most,  if  not  all,  of  the 
household  remedies  are  there  described. 


PROBLKAI   (^UICSTIOXS  279 

Try  to  answer  the  f()ll()\vin«i;  practical   (lucstions  on  first  aid  : 

1.  What  would  you  do  to  prevent  bleedinj;  fnjni  a  cut  from  wliich 
blood  issued  in  jets  or  spurts? 

2.  What  would  you  do  in  case  of  convulsions? 

3.  How  would  you  treat  jioisonin^  in  its  first  stages? 

4.  If  you  knew  what  the  substance  was  that  a  person  had 
absorbed  or  taken  as  a  poison,  what  would  you  then  ijo?  Hive 
three  or  four  different  instances,  taking  common  j)()isons  in  each 
case. 

5.  What  would  you  do  in  a  case  of  fainting?    Drowning? 

6.  How  would  you  treat  a  case  of  sunstroke  ?     Heat  exhaustion  ? 

7.  What  would  3^ou  do  in  the  case  of  a  l)urn ? 

8.  How  would  you  treat  a  bad  sprain  ? 

9.  How  would  you  go  to  work  to  treat  a  person  who  has  fallen 
and  fractured  his  arm  or  leg  ? 

10.  How  would  you  treat  a  cut  from  a  rusty  or  dirty  metal 
instrument  ? 

11.  How  would  you  treat  a  cold?  A  case  of  indigestion? 
Sick  headache?     Summer  complaint? 

Conclusion.  —  Are  you  prepared  to  meet  an  emergency  re- 
quiring first  aid  ? 

Problem  Questions 

1.  What  home  conditions  do  you  personally  have  control 
over?     How  would  you  go  about  to  improve  them? 

2.  What  school  conditions  might  you  control?  What  would 
you  do  to  improve  them  ? 

3.  What  methods  of  ventilation  are  best  lor  a  schoolroom  and 
why?     Illustrate  with  diagrams. 

4.  How  would  you  ventilate  your  IxMlroom  so  a.s  to  insure  fresh 
air  but  no  draft  on  the  bed'.'  I'se  a  diagram  to  explain  your 
answer. 

5.  Why  is  sunlight  important  for  every  bedroom? 

6.  ''  We  spend  one  third  of  (Mir  life  in  our  bedroom.  Why  not 
have  it  cozy  and  well  hlled  with  fuiiiiture.  hangings,  and  rue???" 
Criticize  this  statement  from  the  hygienic  standpoint. 

7.  Why  is  a  damp  cloth  the  b(>st  means  of  dusting  a  bedroom  ? 


280     MAN'S   IMPROVEMENT   OF   HIS   ENVIRONMENT 

8.  Why,  in  moving  into  a  new  apartment,  should  the  tenant 
insist  on  complete  renovation  ? 

9.  What  method  of  heating  is  best  and  why?     Explain  fully. 

10.  Give  three  rules  which  will  help  prevent  insect  pests  in  an 
apartment. 

11.  Why  is  illuminating  gas  a  dangerous  friend  at  times? 

12.  Give  three  good  school  luncheon  menus  and  tell  why  they  are 
good. 

13.  In  what  respects  is  factory  inspection  biological? 

14.  Why  should  foods  be  regularly  inspected  in  a  city? 

15.  How  is  our  city  milk  supply  safeguarded?  (See  your 
Sanitary  Code.) 

16.  Show  three  ways  in  which  a  city  may  protect  its  water 
supply. 

17.  To  what  extent  might  a  filter  attached  to  a  faucet  be  useful  ? 
Why  would  it  not  be  likely  to  be  effective  against  germs? 

18.  Why  is  typhoid  fever  considered  a  country  rather  than  a 
city  disease? 

19.  What  is  the  work  of  the  department  of  street  cleaning? 
How  can  you  help  in  this  work? 

20.  What  is  immunity  ? 

21.  What  is  the  theory  underlying  the  practice  of  vaccination? 
How  does  this  treatment  differ  from  the  antitoxin  treatment  for 
diphtheria  ? 

22.  What  is  the  method  of  vaccination  for  typhoid?  Has  this 
method  proved  of  value  ? 

23.  How  may  you  cooperate  with  the  department  of  health  in 
your  city? 

Reference  Books 

Hunter,  Civic  Biology,  Chap.  XXIV.     American  Book  Company. 

Hunter,  Elements  of  Biology,  pp.  317-428.     American  Book  Company. 

Hunter,  Essentials  of  Biology,  Chap.  XXIX.     American  Book  Company. 

Allen,  Civics  and  Health.     Ginn  and  Company. 

Allen,  The  Man  of  Perfect  Health.     World's  Work,  July,  1909. 

Andrews,  The  White  Peril.     "White  Peril  Company,  Danbury,  Conn. 

Annual  Report  of  Department  of  Health,  City  of  New  York  (and  other  cities). 

A  War  on  Consumption.     Metropolitan  Life  Insurance  Company. 

Banks,  The  Problems  of  Youth.     Funk  and  Wagnalls  Company. 

Barry,  Hygiene  of  the  Schoolroom.     Silver,  Burdett  and  Company. 


REFERENCE   BOOKS  281 

Bashoro,  Ouflines  of  Practical  Sanitation.     John  Wiley  and  Sons. 

Bell,  Our  Teeth,  How  to  Take  Care  <>/  Them.      Voium  American  PuMishujK  ( 'oinpany. 

Bjorkman,  What  Health  is  Worth  to  Us.      Worl/Tti  Wurk,  March.  1*.»(K<. 

Bosworth,  Taking  Cold.     C.  S.  Davis,  Detroit. 

Brown,  Health  in  Home  and  Town.     D.  C'.  Heath  and  Company. 

Bryce,  Laws  of  Life  and  Health.     ,).  B.  Lippincott  Company. 

Bulletins  and  Publications  of  Committee  of  One  Hundred  on  National  Health. 

Burbank,  Training  of  the  Human  Plant.     Century  Conii>;iny. 

Burton-Fanning,  Open  Air  Treatment  of  Pulmvnary  Tulirrculosis.      I'aul  Ji.  HoIUt. 

Carrington,  Directions  for  Living  and  Sleeping  in  the  Open  Air.     Metroixjlitan  Life 

Insurance  Company. 
Cavanagh,  Care  of  the  Body.     E.  P,  Dutton  and  Company. 
Chapin,  Municipal  Sanitation  in  the  United  States.     Snow  and  Farnham. 
Chapin,  Sources  and  Modes  of  Infection.     John  Wiley  and  Sons. 
Chappell,  The  House  Fly  —  Man  Killer.     Pearson's  Mngazinr,  .lurn',  1910. 
Clarke,    Vital  Economy,  or  How  to  Conserve  your  Strength.     We.ssels  and   BisscU 

Company. 
Coleman,  The  People's  Health.     The  Macmillan  Company. 
Conklin,  Heredity  and  Environment.     Princeton  l^niversity  Press. 
Conn,  Practical  Dairy  Bacteriology.     Oranfxe  JucUl  Company. 

Creelman,  Is  Typhoid  to  be  conquered  at  Last .'     Pearson's  Magazine,  Decern lx?r,  1909. 
Curtis,  Nature  and  Health.     Henry  Holt  and  Company. 
Ditmar,  Home  Hygiene  and  Prevention  of  Disease.     Duffield  and  Company. 
Doane,  Insects  and  Disease.    Henry  Holt  and  Company. 
Dock,  Hygiene  and  Morality.     G.  P.  Putnam's  Sons. 

Dorr,  A  Fighting  Chance  for  the  City  Child.     Hampton's  Magazine,  July,  1910. 
Dorset,  Some  Common  Disinfectants.      Farmers'  Bulletin  345,  U.  S.  Department 

of  Agriculture,  1908. 
Dressier,  School  Hygiene.     The  Macmillan  Company. 

Du  Puy  and  Brewster,  Our  Duel  with  the  Rat.     McClurc's  Magazine,  May.  1910. 
Egbert,  A  Manual  of  Hygiene  and  Sanitation.     The  Macmillan  Company. 
Fisher,  A  Departmerd  of  Dollars  vs.  A  Department  of  Health.     McClurc's  Magazine, 

July,  1910. 
Fisher,  National  Vitality.     Senate  Document  No.  G7G,  Vol.  III.  COth  ConRresi*. 
Frankland,  Bacteria  in  Daily  Life.     Longmans,  Green  and  Company. 
Godfrey,  The  Health  of  the  City.     Houghton  Mifflin  Company. 
Goler,  Teeth,  To7isils,  Adenoids.      Metropolitan  Life  Insurance  Company. 
Grinnell,  Our  Army  versus  a  Bacilltis.      National  Cieographi<-  .Magazine. 
Gulick,  The  Efficient  Life.      Doubleda.\-,  Page  and  Company. 
Health  News.     Monthly  Bulletin  of  New  York  State  Department  of  Health. 
Hemns,  Malaria  —  Cause  and  Control.     The  Macmillan  Conip-'my. 
Home  Care  of  the  Sick.     Library  of  Hcmie  Economics,  Chicago. 
Horsley  and  Sturge.  Alcohol  and  the  Human  Body.     Tin-  M.icmillan  Company. 
Hough  and  Sedgwick.  The  Human  Mechanism.      Part  II.     (linn  and  Company. 
Howard,  The  House  Fly  the  Disea.'<e  Carrier.      F.  .\.  Stokes  Company. 
Huber,  Consumption  and  Civilization.     .1.  M.  Lippincott  Conii>any. 
Hutchinson,     Common    Diseases.         Ifandhook    of    Htnlth.     PrcrrnlahJe    DiJtctue*. 

Houghton  Mifflin  Company. 
Hutchinson,  Sound  Bodies  for  Sound  Minds.     (!o<y{  Ifousckeeping.  Sep(omlH»r.  I'.H  I. 


W.  C.  State  CtXkm 


282    MAN'S   IMPROVEMENT   OF   HIS   ENVIRONMENT 

Hutchinson,  The  Child's  Day.     Houghton  Mifflin  Company. 

Jacobs,  Fake  Consumption  Cures.     Metropolitan  Life  Insurance  Company. 

Jewett,  Body  and  its  Defenses.     Ginn  and  Company. 

Lee,  Scientific  Features  of  Modern  Medicine.     Columbia  University  Press. 

Lewis,   The  Warfare  against  Tuberculosis.     Review  of  Reviews,  September,   1908. 

Lippert,  F.  E.  &  H.  A.,  When  to  send  for  the  Doctor  and  WJmt  to  do  before  the  Doctor 
Comes.     J.  B.  Lippincott  Company. 

Lorand,  Old  Age  Deferred.     F.  A.  Davis  Company. 

Lynch,  First  Aid  in  the  Home.     Metropolitan  Life  Insurance  Company. 

Macfie,  Air  and  Health.     Methuen  and  Company,  London. 

Mason,  A  Plea  for  Wider  Sanitary  Science  Knowledge.     Science,  February,  1910. 

Metchnikov,  E.,  Prolongation  of  Life.     G.  P.  Putnam's  Sons. 

Metropolitan  Magazine.     Metropolitan  Life  Insurance  Company. 

Millard,  Building  and  Care  of  the  Body.     The  Macmillan  Company. 

Morrison  and  Hilditch,  Does  Money  Carry  Disease?     Literary  Digest,  March,  1910. 

Morrison,  The  Transmission  of  Disease  by  Money.  Popular  Science  Monthly, 
January,  1910. 

Morrow,  The  Immediate  Care  of  the  Engine.     W.  B.  Saunders. 

Morse,  The  Collection  and  Disposal  of  Municipal  Waste.  Municipal  Journal  and 
Engineer. 

Otis,  The  Great  White  Plague.     T.  Y.  Crowell  Company. 

Overlook,  The  Working  People,  Their  Health  and  How  to  Protect  It.  Massachusetts 
Health  Book  Publishing  Company. 

Overton,  General  Hygiene.     American  Book  Company. 

Pamphlets,  Nos.  4,  6,  14,  15,  21,  26,  34.  Russell  Sage  Foundation  Department  of 
Child  Hygiene. 

Personal  Hygieyie.     Library  of  Home  Economics,  Chicago. 

Price,  Handbook  of  Sanitation.     John  Wiley  and  Sons. 

Pure  Milk  and  Human  Life.     Success,  March,  1909. 

Pyle,  A  Manual  of  Personal  Hygiene.     W.  B.  Saunders. 

Ramaley  and  Giffin,  Prevention  and  Control  of  Disease.     F.  Ramaley,  Col. 

Rats  as  Pests.     Farmers'  Bulletin  369,  U.  S.  Department  of  Agriculture. 

Richards,  Euthenics,  the  Science  of  Controllable  Environment.  Whitcomb  and  Bar- 
rows. 

Richards,  Sanitation  in  Daily  Live.     Whitcomb  and  Barrows. 

Richman  and  Wallach,  Good  Citizenship.     American  Book  Company. 

Ritchie,  Primer  of  Sanitation.     World  Book  Company. 

Roc,  The  Physical  Nature  of  the  Child.     (Advanced.)     The  Macmillan  Company. 

Rogers,  Life  and  Health.     J.  B.  Lippincott  Company. 

Rosenau,  Preventive  Medicine  and  Hygiene.     D.  Appleton  and  Company. 

Ross,  The  Reduction  of  Domestic  Flies.     John  Murray,  London. 

Sadler,  The  Cause  and  Cure  of  Colds.     A.  C.  McClurg  and  Company. 

Sadler,  The  Science  of  Living,  or  the  Art  of  Keeping  Well.  A.  C.  McClurg  and  Com- 
pany. 

Sanitary  Drinking  Cups.     Bulletin,  Kansas  Board  of  Health,  No.  3,  1909. 

School  Hygiene.     American  School  Hygiene  Association. 

Seymore,  Better  Stock  Miracle.     Country  Life,  January,  1914. 

Sharpe,  Laboratory  Manual  in  Biology,  pp.  320-334.     American  Book  Company. 

Shaw,  School  Hygiene.     The  Macmillan  Company. 


REFKKi:XCE   BOOKS  283 

Smallpox  and  its  Prevention.     Metropolitan  Life  lusunincc  r'ompany. 

Terman,  The  Teacher's  Health.     Hounliton  Mifflin  Company. 

The  Child.     Metropolitan  Life  Insurance  Company. 

Thomas,  Ventilation,  Heating,  and  Management  of  Church> ■•!  and  Publir  BuildinQM. 
Longmans,  Green  ond  Company. 

Tolman,  Hygiene  for  the  Worker.     American  Book  Company. 

Typhoid  Fever  and  How  to  Prevent  it.     Metropolitan  Life  In.snranre  Company. 

YeiWer,  Hotising  Reform  :  a  Handbook  for  Practical  Use  in  American  Ciiiea.  Chari- 
ties Publishing  Company. 

White,  The  Occupation  and  Exercise  Cure.     Outlook,  March.   I'UO. 

Winslow,  The  Health  of  the  Worker.      Metropolitan  Life  Insurance  Company. 

Woodworth,  The  Care  of  the  Body.     The  Macmillan  Company. 

Zinsser,  Infection  and  Resistance.     The  Macmillan  Company. 


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